We report a wavelength-locked 914 nm laser diode in-band pumped intra cavity efficient green laser, in our experiment, a wave-locked 914 nm laser diode was used as a pumping source, which improve pump uniformity and pump efficiency and reducing the thermal effect of the laser greatly, thus, a high beam quality 532 nm laser output is obtained. When the pump power is 18 W and the repitition rate is 130 kHz, a green laser output of 6.7 W is obtained, and the conversion efficiency is 37.2% for pumping power of 18 W, which corresponds to a conversion efficiency of 60% for absorbed pumping.
High-Sensitivity HydrophoneBased on Fiber Grating Laser And Acorrugated Diaph...IJRESJOURNAL
ABSTRACT: In this work, we present afiber optic hydrophones based on dual-frequency fiber grating lasers and a corrugated diaphragm. The laser is employed as sensing element and an elastic corrugated diaphragm is used to translate acoustic pressure P intolateral point loadNon the laser cavity. Experimental result shows the fiber laser hydrophone has a working bandwidth over 1 kHz with sub100 μPa/Hz1/2minimum detectable pressure at 1 kHz
You will find here all the elements presented by the CENAPT team ( Drs. Guido Pauli and Charlotte Simmler) and pertaining to the NMR workshop at the American Society of Pharmacognosy (ASP 2017, Portland Oregon).
These slides summarize the different steps related to the implementation of quantitative NMR for purity analysis.
Graphene Nanoplatelets (GnP)-PVA Based Passive Saturable AbsorberTELKOMNIKA JOURNAL
A passive Q-switched pulsed laser at 1.5 m region incorporating graphene nanoplatelets (GnPs)
embedded in Polyvinyl Alcohol (PVA) is demonstrated. A surfactant is used to aid the dispersion of the
GnPs before it is mixed with PVA to develop a GnPs-PVA film based SA. The SA is integrated into the
laser cavity by attaching a cut of the GnPs-PVA film in between two fiber ferrule of the laser ring cavity.The
proposed GnPs-PVA film based passive Q–switched laser was able to operate as the input pump power
was increased from 39 mW up to a maximum of 148 mW before diminishing. The laser obtained operated
with a central wavelength of 1530.76 nm. Repetition rates were obtained at 33 kHz to 91.5 kHz, throughout
the tunable input pump power with the shortest pulse width of 2.42 s. Maximum attainable peak power
and pulse energy of 1.2 mW and 5.9 nJ, respectively, was recorded, accompanied by a signal to noise
ratio (SNR) of 28 dB.
This was a presentation by me for a Seminar For My Pharm. Analysis class. I have tried well to include possible things but haven't gone much in deep because it would be irrelevant as per syllabus. If any mistakes, Please do leave a comment
Application Note: Simple Method of Measuring the Band Gap Energy Value of TiO...PerkinElmer, Inc.
The measurement of the band gap of materials is important in the semiconductor, nanomaterial and solar industries. This note demonstrates how the band gap of a material can be determined from its UV absorption spectrum.
BASIC CONCEPT OF RADIATION SHIELDING AND ITS CALCULATION TECHNIQUES mahbubul hassan
Training Course on Radiation Protection for Radiation Workers
and RCOs of BAEC, Medical Facilities & Industries
24 - 28 October 2021
Training Institute
Atomic Energy Research Establishment, Savar, Dhaka
High-Sensitivity HydrophoneBased on Fiber Grating Laser And Acorrugated Diaph...IJRESJOURNAL
ABSTRACT: In this work, we present afiber optic hydrophones based on dual-frequency fiber grating lasers and a corrugated diaphragm. The laser is employed as sensing element and an elastic corrugated diaphragm is used to translate acoustic pressure P intolateral point loadNon the laser cavity. Experimental result shows the fiber laser hydrophone has a working bandwidth over 1 kHz with sub100 μPa/Hz1/2minimum detectable pressure at 1 kHz
You will find here all the elements presented by the CENAPT team ( Drs. Guido Pauli and Charlotte Simmler) and pertaining to the NMR workshop at the American Society of Pharmacognosy (ASP 2017, Portland Oregon).
These slides summarize the different steps related to the implementation of quantitative NMR for purity analysis.
Graphene Nanoplatelets (GnP)-PVA Based Passive Saturable AbsorberTELKOMNIKA JOURNAL
A passive Q-switched pulsed laser at 1.5 m region incorporating graphene nanoplatelets (GnPs)
embedded in Polyvinyl Alcohol (PVA) is demonstrated. A surfactant is used to aid the dispersion of the
GnPs before it is mixed with PVA to develop a GnPs-PVA film based SA. The SA is integrated into the
laser cavity by attaching a cut of the GnPs-PVA film in between two fiber ferrule of the laser ring cavity.The
proposed GnPs-PVA film based passive Q–switched laser was able to operate as the input pump power
was increased from 39 mW up to a maximum of 148 mW before diminishing. The laser obtained operated
with a central wavelength of 1530.76 nm. Repetition rates were obtained at 33 kHz to 91.5 kHz, throughout
the tunable input pump power with the shortest pulse width of 2.42 s. Maximum attainable peak power
and pulse energy of 1.2 mW and 5.9 nJ, respectively, was recorded, accompanied by a signal to noise
ratio (SNR) of 28 dB.
This was a presentation by me for a Seminar For My Pharm. Analysis class. I have tried well to include possible things but haven't gone much in deep because it would be irrelevant as per syllabus. If any mistakes, Please do leave a comment
Application Note: Simple Method of Measuring the Band Gap Energy Value of TiO...PerkinElmer, Inc.
The measurement of the band gap of materials is important in the semiconductor, nanomaterial and solar industries. This note demonstrates how the band gap of a material can be determined from its UV absorption spectrum.
BASIC CONCEPT OF RADIATION SHIELDING AND ITS CALCULATION TECHNIQUES mahbubul hassan
Training Course on Radiation Protection for Radiation Workers
and RCOs of BAEC, Medical Facilities & Industries
24 - 28 October 2021
Training Institute
Atomic Energy Research Establishment, Savar, Dhaka
Abstract
Terahertz sub-surface imaging offers an effective solution for surface and 3D imaging because of minimal
sample preparation requirements and its ability to “see” below the surface. Another important property is the ability
to inspect on a layer-by layer basis via a non-contact route, non-destructive route. Terahertz 3D imager designed
at Applied Research and Photonics (Harrisburg, PA) has been used to demonstrate reconstructive imaging with a
resolution of less than a nanometer. Gridding with inverse distance to power equations has been described for 3D
image formation. A continuous wave terahertz source derived from dendrimer dipole excitation has been used for
reflection mode scanning in the three orthogonal directions. Both 2D and 3D images are generated for the analysis
of silver iodide quantum dots’ size parameter. Layer by layer image analysis has been outlined. Graphical analysis
was used for particle size and layer thickness determinations. The demonstrated results of quantum dot particle
size checks well with those determined by TEM micrograph and powder X-ray diffraction analysis. The reported
non-contact measurement system is expected to be useful for characterizing 2D and 3D naomaterials as well as for process development and/or quality inspection at the production line.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Minimize MIMO OFDM interference and noise ratio using polynomial-time algorit...IJECEIAES
In the distributed transmit antenna MIMO OFDM system, each transmitting antenna has different frequency offset between each transmitting antenna and receiver due to the use of independent crystal oscillator. This paper proposes Polynomial-time algorithm for correcting the frequency offset in a received signal by maximizing the conditional average signal. The algorithm focus on reducing to interference and noise ratio of each subcarrier on the receiving antenna by frequency offset. The simulation result shows the performance of the proposed algorithm is slightly improved compared with the existing frequency offset correction algorithm, and the complexity is reduced by 50% or more.
A high efficient narrow linewidth fiber laser based on fiber Bragg grating Fabry-Perot (FBG F-P) cavity was demonstrted. The spatial hole burning effect was restrained by fiber Faraday rotator(FR). Two short FBG F-P cavities as narrow bandwidth filters discriminated and selected the laser longitudinal modes efficiently. Stable single frequency 1550nm laser was acquired. Pumped by two 976nm LD, the fiber laer exhibited a 11mW threshold. The 73mW output power was obtained upon the maximum 145mW pump power. The optical-optical efficciency was 50 and the slope efficiency was 55. The 3dB linewidth of laser was less than 10kHz, measured by the delayed self-heterodyne method with 10km mono-mode fiber. The high power narrow linewidth fiber lasr can be used in high resolution fiber sensor system .
Light sources based on optical-scale acceleratorsGil Travish
Presented at the 2010 Future Light Sources Workshop, SLAC, Palo Alto, CA. Gives an overview of optical-scale particle accelerator structures as would be used in x-ray light sources.
Design of Rare Earth Ion Doped Polymer Waveguide LasersIJERA Editor
The laser performance of rare earth ion Nd3+-complex-doped polymer channel waveguides was investigated using a continuous-wave excitation at 800 nm. CW laser operation was achieved near 1060.2 nm and 878 nm in Nd3+-complex-doped polymer channel waveguides with output powers of up to 0.98 mW and 0.20 mW, respectively. The stability of the laser output was examined with CW excitation. To the best of our knowledge, this is the first report of a rare-earth-ion-doped polymer waveguide laser as well as a CW solid-state polymer laser.
Abstract
Terahertz sub-surface imaging offers an effective solution for surface and 3D imaging because of minimal
sample preparation requirements and its ability to “see” below the surface. Another important property is the ability
to inspect on a layer-by layer basis via a non-contact route, non-destructive route. Terahertz 3D imager designed
at Applied Research and Photonics (Harrisburg, PA) has been used to demonstrate reconstructive imaging with a
resolution of less than a nanometer. Gridding with inverse distance to power equations has been described for 3D
image formation. A continuous wave terahertz source derived from dendrimer dipole excitation has been used for
reflection mode scanning in the three orthogonal directions. Both 2D and 3D images are generated for the analysis
of silver iodide quantum dots’ size parameter. Layer by layer image analysis has been outlined. Graphical analysis
was used for particle size and layer thickness determinations. The demonstrated results of quantum dot particle
size checks well with those determined by TEM micrograph and powder X-ray diffraction analysis. The reported
non-contact measurement system is expected to be useful for characterizing 2D and 3D naomaterials as well as for process development and/or quality inspection at the production line.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Minimize MIMO OFDM interference and noise ratio using polynomial-time algorit...IJECEIAES
In the distributed transmit antenna MIMO OFDM system, each transmitting antenna has different frequency offset between each transmitting antenna and receiver due to the use of independent crystal oscillator. This paper proposes Polynomial-time algorithm for correcting the frequency offset in a received signal by maximizing the conditional average signal. The algorithm focus on reducing to interference and noise ratio of each subcarrier on the receiving antenna by frequency offset. The simulation result shows the performance of the proposed algorithm is slightly improved compared with the existing frequency offset correction algorithm, and the complexity is reduced by 50% or more.
A high efficient narrow linewidth fiber laser based on fiber Bragg grating Fabry-Perot (FBG F-P) cavity was demonstrted. The spatial hole burning effect was restrained by fiber Faraday rotator(FR). Two short FBG F-P cavities as narrow bandwidth filters discriminated and selected the laser longitudinal modes efficiently. Stable single frequency 1550nm laser was acquired. Pumped by two 976nm LD, the fiber laer exhibited a 11mW threshold. The 73mW output power was obtained upon the maximum 145mW pump power. The optical-optical efficciency was 50 and the slope efficiency was 55. The 3dB linewidth of laser was less than 10kHz, measured by the delayed self-heterodyne method with 10km mono-mode fiber. The high power narrow linewidth fiber lasr can be used in high resolution fiber sensor system .
Light sources based on optical-scale acceleratorsGil Travish
Presented at the 2010 Future Light Sources Workshop, SLAC, Palo Alto, CA. Gives an overview of optical-scale particle accelerator structures as would be used in x-ray light sources.
Design of Rare Earth Ion Doped Polymer Waveguide LasersIJERA Editor
The laser performance of rare earth ion Nd3+-complex-doped polymer channel waveguides was investigated using a continuous-wave excitation at 800 nm. CW laser operation was achieved near 1060.2 nm and 878 nm in Nd3+-complex-doped polymer channel waveguides with output powers of up to 0.98 mW and 0.20 mW, respectively. The stability of the laser output was examined with CW excitation. To the best of our knowledge, this is the first report of a rare-earth-ion-doped polymer waveguide laser as well as a CW solid-state polymer laser.
A novel C+ L band erbium doped fiber broadband light so urce w ith hig h power was introduced. In the ex periment, a fiber loop mirr or made fr om 3 dB coupler was employed, mean while, power controlling circuit made fiber output steady. Single stage fiber and two pump LDs of 980 nm was used, and C band amplified spontaneous emission of backw ard again enhanced the efficiency of LD and stability o f output of fiber. Mean while, selecting appropriate Erbium doped fiber length simultaneously g ot output of C+ L band with power higher than 26.67 mW ( 14.26 dBm) , whose average wavelength was 1 550.887 nm.
A high efficient narrow linewidth fiber laser based on fiber Bragg grating Fabry- Perot( FBG F- P) cavity was demonstrted. The spatial hole burning effect was restrained by fiber Faraday rotator( FR) . Two short FBG F- P cavities as narrow bandw idth filters discriminated and selected the laser longitudinal modes efficiently. Stable single frequency 1550nm laser was acquired. Pumped by two 976nm LD, the fiber laer exhib ited a 11 mW threshold. The 73mW output power was obtained upon the maximum 145mW pump power. The optica-l optical efficciency was 50% and the slope efficiency was 55% . T he 3 dB linewidth of laser was less than 10 kHz, measured by the delayed sel-f heterodyne method with 10 km mono- mode fiber. T he high power narrow linewidth fiber lasr can be used in high resolution fiber sensor system.
Module of fiber coupled diode laser based on 808nm single emitter combinationNaku Technology Co,. Ltd
Because of the good beam quality and heat dissipation of single emitter diode laser, it is more resuitable to be used in the source of electro-optic countermeasure. Aim at the responer curve of charge-coupled device (CCD) spectrum, 808nm single emitter is used as unitsource and 24 single emitters are divided into four groups. In order to increase the output power intensity, space sombination and polarization combination are used in the experiment. Combined beam is focused in an optical fiber through the focused lens group designed by ourself. All the single emittwes are connected inseries. When the drive current is 8.5A, 162W output power is obtained from a 300um fiber core with a numerical aperture of 0.22 at 808nm and coupling efficiency of 84%.
Observation of dark and bright pulses in q-switched erbium doped fiber laser ...journalBEEI
In this paper, a passively Q-switched Erbium doped fiber laser (EDFL) by residing Graphene nanoplatelets (GnPs) embedded in polyvinyl alcohol (PVA) based saturable absorber (SA) is demonstrated. To aid the dispersion of GNPs, a surfactant is used and then it is mixed with polyvinyl alcohol (PVA) as host polymer to develop GnPs-PVA film based passive SA. The GnPs-PVA based film then integrated in laser cavity in ring cavity configuration for pulse laser generation. The experimental works show that the proposed passive SA operates at input pump power range from 77 mW to 128 mW with a tunable repetition rate from 78.4 kHz to 114.8 kHz and a shortest pulse width of 3.69 µs. The laser produces maximum instantaneous output peak power and pulse energy of 7.3 mW and 30.46 nJ, respectively and accompanied by signal to noise ratio (SNR) of 64 dB.
Observation of dark and bright pulses in q-switched erbium doped fiber laser ...journalBEEI
In this paper, a passively Q-switched Erbium doped fiber laser (EDFL) by residing Graphene nanoplatelets (GnPs) embedded in polyvinyl alcohol (PVA) based saturable absorber (SA) is demonstrated. To aid the dispersion of GNPs, a surfactant is used and then it is mixed with polyvinyl alcohol (PVA) as host polymer to develop GnPs-PVA film based passive SA. The GnPs-PVA based film then integrated in laser cavity in ring cavity configuration for pulse laser generation. The experimental works show that the proposed passive SA operates at input pump power range from 77 mW to 128 mW with a tunable repetition rate from 78.4 kHz to 114.8 kHz and a shortest pulse width of 3.69 µs. The laser produces maximum instantaneous output peak power and pulse energy of 7.3 mW and 30.46 nJ, respectively and accompanied by signal to noise ratio (SNR) of 64 dB.
A novel C+ L band erbium doped fiber broadband light so urce w ith hig h power was introduced. In the ex periment, a fiber loop mirr or made fr om 3 dB coupler was employed, mean while, power controlling circuit made fiber output steady. Single stage fiber and two pump LDs of 980 nm was used, and C band amplified spontaneous emission of backw ard again enhanced the efficiency of LD and stability o f output of fiber. Mean while, selecting appropriate Erbium doped fiber length simultaneously g ot output of C+ L band with power higher than 26.67 mW ( 14.26 dBm) , whose average wavelength was 1 550.887 nm.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The method presented in this paper is beased on coupled line in the standard schiffman phase shifters structure and replace it
with lange coupler. To having a wider bandwidth, the stronger coupling is required. One way to achieve strong coupling is using of the
parallel coupled lines that this property exist in the lange coupler. So this paper discusses the design of fixed broadband phase shifter
by using the lange coupler and a novel phase shifters will be introduced according to the standard schiffman phase shifters. Finally
optimal parameters to achieve the desired performance will be shown.
1550nm 1MHz narrow linewidth fiber laser is a high-precision, high-performance optical device. It uses optical fiber as the gain medium and generates a laser with a wavelength of 1550 nanometers through the excitation of rare earth elements. It has an extremely narrow linewidth (1MHz), thus ensuring high frequency stability and narrow bandwidth characteristics. This laser has important applications in spectral analysis, optical interference, fiber-optic communication and other fields, and can provide high-resolution and accurate measurement results. At the same time, its high beam quality is suitable for industrial fields such as precision machining and laser cutting. In short, the 1550nm 1MHz narrow linewidth fiber laser is a versatile, high-performance light source that can meet the needs of various precision measurements and industrial applications.
This is a 375nm 30mW polarization-maintaining fiber-coupled laser. Its fiber is pluggable. When installing the fiber, pay attention to align the bayonet.
The laser output power is adjustable from 1 to 30mW. This laser supports CW continuous operation and TTL modulation operation modes, and is equipped with a modulation signal line. When Modulation is connected to an external signal, the laser automatically enters TTL modulation mode.
The 1550nm 10kW pulsed nanosecond fiber laser is a shining star in modern industrial technology. Its high power output and precise nanosecond pulse control make it an ideal choice for material processing, scientific research experiments and other fields. With its unique fiber structure, this laser achieves high efficiency, long life and stability, bringing revolutionary changes to industrial production. In the future, it will continue to lead the new trend of laser technology and contribute to scientific and technological progress and industrial development.
In today's laser technology field, the 980nm 500mW TEM00 semiconductor laser has become the focus of scientific researchers and technicians with its unique optical properties and wide application prospects. This laser provides strong technical support for research and applications in many fields with its high-precision and high-efficiency laser output.
Erbium doped fiber amplifier (EDFA) is a high performance, small size of the fiber amplifier products. The internal use of stability high power semiconductor laser, the high stability of WDM, isolator, and high gain erbium-doped fiber. The product has the advantages of high reliability, high power output, high gain and low noise.
It is a C+L Band 26dBm EDFA Amplifier.The wavelength Range is 1528~1563nm & 1570~1603nm. The EDFA supports two working modes, ACC and APC, and the two working modes can be switched. In APC mode, the output power can be adjusted. In ACC mode, the operating current can be adjusted. Our desktop EDFA can be controlled by buttons. PC control software can be connected through RS232 serial port.
What our laboratory introduces today is a 1550nm 10kW nanosecond pulse fiber laser.
First, let's take a look at the wavelength characteristics of the 1550nm nanosecond fiber laser. 1550nm is located in the infrared spectrum range and belongs to near-infrared light. Laser of this wavelength shows excellent transmission performance in optical communications, which can effectively reduce fiber loss and improve communication efficiency. At the same time, in the fields of medical treatment and material processing, the 1550nm laser has strong penetration and can achieve precise treatment of deep tissues and fine processing of high-hardness materials.
This is a 1550nm fiber-coupled acousto-optic modulator with a driver. The 1550nm acousto-optic modulator is an external modulation technology, and the acousto-optic device that controls the intensity of the laser beam is usually called an acousto-optic modulator. The 1550nm AOM has the advantages of high modulation extinction ratio and high power withstand, and is widely used in the field of optical fiber sensing.
As can be seen from the video, this is a fiber optic coupling device, which is a multi-mode fiber and the fiber is pluggable. The coupling optical fiber can be customized. The one used here is 100μm, 2m in length, and the interface is FC/PC. There is a buckle on the interface. When installing the optical fiber, insert the optical fiber into the buckle and tighten it.
The one shown in our laboratory today is a 1550nm infrared single-mode fiber coupled laser. This is a desktop laser, and the output power can be adjusted directly through the buttons on the panel. The output power is adjustable with an adjustment range of 0.5~5W. The adjustment accuracy is 1mW. The laser can also be controlled through software, and the communication interface is RS232.
This is a 1550nm 200MHz Fiber Coupled AOM with Driver. It is equipped with single-mode fiber, and polarization-maintaining fiber can also be customized. The radio frequency interface is SMA. We provide customized AOM service, different working wavelength and RF frequency can be customized. The rise/fall time of this modulator is 10ns. Let's check it now.
It is a 637nm 15W red laser system. The high-power laser generates a lot of heat when it works, and a heat sink is added at the bottom of the laser module. The radiator is equipped with 3 fans. When the laser is turned on, be careful not to cover the front and rear to avoid affecting the heat dissipation performance.
High power erbium doped fiber amplifier (EYDFA-HP-BA), based on amplification technology of double clad erbium doped fiber, unique optical packaging technology, and with reliable hardware light path protection design, realized high power laser output in C band or L band, It has the advantages of high gain and low noise, and can be widely used in CATV, optical fiber communication, laser radar, etc..
This is a C-Band Erbium Doped Fiber Amplifier, high gain and low noise. It is the latest style of 2023, with a silver shell. The heat sink of the fiber amplifier is upward. This is Polarization-Maintaining Erbium-Doped Fiber Amplifier, SM Fiber EDFA can also be customized.
The power of 60W is very high power, which can instantly ignite the cardboard. Be sure to pay attention to safety when operating, the operator must wear laser protective glasses, and the laser cannot point to other people or other flammable objects.
532nm DPSS green laser is made features of good beam profile, ultra compact, long lifetime and easy operating, which is widely used in collimation, laser medical treatment, scientific experiment, optical instrument, laser display, etc.
The 1550nm band single-wavelength laser (low power) adopts high-stability semiconductor laser chip, polarization maintaining fiber output, professionally designed drive and temperature control circuit control to ensure the safe and stable operation of the laser, and can provide desktop or modular packaging.
This is 808nm 100mW infrared laser system coupled polarization-maintaining fiber. The working voltage is AC 90~240V and supports wide range voltage. Its laser power can be adjusted from 0~100mW, and it supports two working modes of CW/Modulation.
This is a benchtop ASE broadband light source with button control. This is the broadband light source of C+L Band, the wavelength range is 1528~1603nm. The power can be adjusted, and the adjustment accuracy is 1mW. The single-mode fiber is pluggable, and the interface is easily damaged. The fiber here is fixed and cannot be plugged.
It's a high power Ytterbium-doped optical amplifier, its output power is 37dBm. And high power YDFA built-in 3 cooling fans. The software control function can be customized, and the default is button control. The current working mode, current and output power are displayed on the front display.
https://www.civillaser.com/index.php?main_page=product_info&products_id=3049
It's a high power polarization maintaining ytterbium-doped optical amplifier. Civil Laser's 10W high power YDFA include a 'Monitor' fiber. The software control function can be customized, and the default is button control. The working current or output power can be adjusted by the button.
It supports APC and ACC two working modes can be switched. In APC mode, the output power can be adjusted. In ACC mode, the working current can be adjusted.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Salas, V. (2024) "John of St. Thomas (Poinsot) on the Science of Sacred Theol...Studia Poinsotiana
I Introduction
II Subalternation and Theology
III Theology and Dogmatic Declarations
IV The Mixed Principles of Theology
V Virtual Revelation: The Unity of Theology
VI Theology as a Natural Science
VII Theology’s Certitude
VIII Conclusion
Notes
Bibliography
All the contents are fully attributable to the author, Doctor Victor Salas. Should you wish to get this text republished, get in touch with the author or the editorial committee of the Studia Poinsotiana. Insofar as possible, we will be happy to broker your contact.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
ISI 2024: Application Form (Extended), Exam Date (Out), EligibilitySciAstra
The Indian Statistical Institute (ISI) has extended its application deadline for 2024 admissions to April 2. Known for its excellence in statistics and related fields, ISI offers a range of programs from Bachelor's to Junior Research Fellowships. The admission test is scheduled for May 12, 2024. Eligibility varies by program, generally requiring a background in Mathematics and English for undergraduate courses and specific degrees for postgraduate and research positions. Application fees are ₹1500 for male general category applicants and ₹1000 for females. Applications are open to Indian and OCI candidates.
Lateral Ventricles.pdf very easy good diagrams comprehensive
Wavelength locked 914nm semiconductor laser
1. Wave-locked914 nm laser diode in-band pumped Nd:YVO4 /LBO
A-O Q switched green laser
Li Bin1,2*
Sun Bing2,3
Miao Yinping1
1
School of Electrical and Electronic Engineering, Tianjin University of Technology,
Tianjin 300384, China
2
Tianjin Maiman Laser Technology Co., Ltd., Tianjin 300111, China
3
Key Laboratory of Opto-Electronics Information Science and Technology, Ministry of Education,
College of Precision Instrument and Opto-Electronics Engineering, Institute of Laser and
Opto-Electronics, Tianjin University, Tianjin 300072, China
Abstract We report a wavelength-locked 914 nm laser diode in-band pumped intra cavity
efficient green laser, in our experiment, a wave-locked 914 nm laser diode was used as a pumping
source, which improve pump uniformity and pump efficiency and reducing the thermal effect of
the laser greatly, thus, a high beam quality 532 nm laser output is obtained. When the pump power
is 18 W and the repitition rate is 130 kHz, a green laser output of 6.7 W is obtained, and the
conversion efficiency is 37.2% for pumping power of 18 W, which corresponds to a conversion
efficiency of 60% for absorbed pumping.
Keywords: Wave-locked; Nd:YVO4; In-band pumping;frequency doubling; 532 nm
OCIS Codes:140.3460;140.3480;140.3515;140.3540;140.3580
1 Introduction
Thermal effect is one of the most important factors hindering the further improvement of the
performance of solid-state lasers. Severe thermal effects can lead to deterioration of the beam
quality of the laser, thermal saturation and even thermal cracking of the crystal [1]. In recent years,
people have been looking for ways to reduce the thermal effect of the laser. At present, the most
effective method is to use resonant pumping technology, In-band pumping, which uses pump light
of a specific wavelength to directly pump the ground state atoms to the upper level of the laser,
instead of Pumping to a higher excited state and then relaxing through the non-radiative transition
to the pumping level of the laser, the resonant pumping method eliminates the non-radiative
transition from the excited state to the upper level of the laser, effectively reducing the pump The
quantum loss between the puddle and the oscillating light reduces heat generation and improves
2. quantum efficiency. It can fundamentally solve the thermal effect of the laser, thus effectively
improving the performance of the laser. For the Nd:YVO4 laser resonant pump Pu mainly
concentrated on three pump wavelengths of 880nm, 888nm and 914nm [2-7], theoretically and
experimentally proved that Resonant pumping technology can achieve high power, high beam
quality laser output, but resonant pumping technology still has many shortcomings. First, the
absorption rate of crystals for these wavelengths is relatively low, especially for 914nm absorption
rate. Low, which is not conducive to the improvement of the overall light-to-light conversion rate.
Second, the Nd:YVO4 crystal has a narrow absorption linewidth for these wavelengths, and the
semiconductor laser will shift the emission spectrum with temperature, which is not conducive to
the laser. Adapt to changes in ambient temperature. In order to overcome these shortcomings, we
have adopted wavelength-locked resonance pumping technology, which can effectively overcome
the shortcomings of resonant pumping and further exploit the advantages of resonant pumping.
The so-called lock-wavelength resonance pumping technique is to lock the emission wavelength
of the pump source with a volume Bragg grating (VBG), so that its emission wavelength tends to
be stable, and the change of the external environment temperature has little influence on its
emission spectrum. At the same time, the pump Puyuan's emission spectrum is narrower and more
accurate, corresponding to the absorption spectrum of the working substance. In combination with
the above aspects, the locked-wavelength resonant pumping technique has obvious advantages
over the ordinary resonant pumping technology.
At present, there are not many researches on 914nm resonant pumping technology, and basically
use non-locking wavelength semiconductor lasers or 914nm lasers generated by solid-state lasers
as pump sources. In 2009, Damien Sangla et al reported using 914nm pumped Nd. : YVO4 crystal
laser, when absorbing 14.8W of pump light power, obtained 11.5W of 1064nm laser input
The corresponding light-to-light conversion rate of the absorbed pump light is 78.7%, and the
slope efficiency is 80.7% [8]. In 2013, Chen et al. used 914nm as the pump source of the
regenerative amplifier to reduce the heat load and achieve high The performance of the
regenerative amplifier, and 1nJ, pulse width 5.7ps, frequency 42.7MHz seed regenerative
amplification, and finally get 100kHz, 21.2W regenerative amplification output [9], the same year
Ding Xin et al. using end-pumped 914nm solid The laser is used as a pump source to pump
Nd:YVO4. The 20mm long, doped 2% Nd:YVO4 is used as the gain medium, and the 3.92W
1064nm laser output is obtained at 6.9W injection pumping power. - The light conversion
efficiency is 56.9% [10]. In 2016, Tanant Waritanant et al. used the 914nm pumped Nd:YVO4 to
achieve mode-locked laser output, and obtained a 6.7W, 87MHz mode-locked laser output,
3. corresponding to the absorption of pump light. The slope efficiency is 77.1%, and the light-to-light
conversion efficiency is 60.7% [11]. The above studies all use ordinary semiconductor lasers or
solid-state lasers with non-locking wavelengths as pump sources, and all of them are for the study
of fundamental frequency light. In the case of a semiconductor laser as a pump source, since the
emission line width of the semiconductor laser is wide and the emission wavelength shifts with
temperature, the absorption efficiency of Nd:YVO4 to 914 nm pump light is low, resulting in
overall light. The light conversion efficiency is not high, much lower than the traditional 808nm
pumping method, and the use of the 914nm solid-state laser as the pump source adds complexity
and cost to the system.
In order to overcome the shortcomings of 914nm resonant pumping and take advantage of the
914nm resonant pumping technology, this paper first applied the locked-wavelength 914nm
resonant pumping technique to the Nd:YVO4 intracavity frequency doubled laser, using the pump
source as the center wavelength.
A 913.9nm lock-wavelength fiber-coupled-output semiconductor laser with a linewidth of 0.3nm,
using an acousto-optic Q-switch as a modulator, and a Class I critical phase-matched LBO as a
frequency-doubled crystal for high-frequency, high-beam The mass of 532nm laser output, when
the incident pump power is 18W and the modulation frequency is 130kHz, the highest 6.7W
532nm green light output is obtained, and the overall light-to-light conversion rate is 37.2%,
corresponding to the light-to-light conversion efficiency of the absorbed pump light. With 60%
pulse width and 52 ns, the experimental results show that the overall light-to-light conversion
efficiency can be compared with the traditional 808nm pumping method, and this method can
effectively reduce the thermal effect of the laser and improve the beam quality of the output laser.
2. Experimental device
The experimental device shown in Figure 1 is a 914nm wavelength-locked fiber-coupled
semiconductor laser with a maximum output power of 20W and a linewidth of 0.3nm. This narrow
linewidth can be well matched to the absorption bandwidth of the crystal. The resonance pump has
the disadvantage of narrow absorption band, and the pump source has good temperature stability.
When the heat sink temperature is changed from 10 °C to 40 °C, the center wavelength of the
emission is only moved by 0.6 nm, and the line width is basically maintained. This does not
change, which makes the use of the semiconductor laser as a pump source with extremely high
temperature stability. The transmission fiber has a diameter of 400μm and a numerical aperture
of 0.22. The Coupler is an optical coupling system. After the coupling system, the pump spot
diameter is about ~700μm, M1 is plated with a 1064nm high-reflection film, and the laser crystal
4. size is 3×3×20mm 3,1. % doped, crystals are wrapped in indium foil and placed in a copper heat
sink. M2 is plated with 914nm anti-reflection and 1064nm high-reaction film system, M3 plated
with 532nm anti-reflection and 1064nm high-reaction film system, M4 plated with 1064nm and
532nm
High-reaction film system, AO is acousto-optic Q switch, its ultrasonic frequency is 80MHz,
RF power is 20W, double-sided coated with 1064nm anti-reflection film, LBO is 3x3x15mm,
Class I critical phase matching method, cutting angle is θ=90 °, φ=11.2°, placed in a high-
precision temperature control box with a temperature control accuracy of ±0.03 °C, coated with
1064nm and 532nm anti-reflection coatings at both ends, and the distance from the right end of
M1 to Nd:YVO4 is 100mm, M2 to The distance from the left end of Nd:YVO4 is 20mm, and the
distance from M2 to M3 is 80mm.
The distance from M3 to M4 is 40mm, and M1, M2, M3, and M4 are flat mirrors.
Fig 1 setup and light path of wavelength-locked laser diode in-band
pumped Nd:YVO4 /LBO green laser
Figure 2 shows the spot size distribution in the cavity. It can be seen from the calculation
results that the fundamental mode spot diameter on the Nd:YVO4 crystal is 624μm, which has a
good pattern matching with the 700μm pump light. In addition, it is larger. The pump spot can
further reduce thermal effects while reducing the up-conversion effect of highly doped Nd:YVO4
crystals.
6. Fig 2 Spot distribution in the cavity
3. Analysis of results
First, we tested the absorption of pump light by Nd:YVO4. When the crystal heat sink
temperature is 25 °C, 1% doping,
The 20mm long Nd:YVO4 absorbs 62% of the 914nm pump light. Figure 3 shows the
relationship between the output 532nm laser power and the incident pump power at different
modulation frequencies. It can be seen from the experimental results that when the pump power is
18W and the modulation frequency is 130kHz, a 532nm laser output of up to 6.7W can be
obtained, corresponding to the light-to-light conversion rate of the incident pump light.
37.2%, the light-to-light conversion rate corresponding to the absorbed pump light is 60%, and
the modulation frequency is 170 kHz, the green light output of 5.7W is obtained, and the light-to-
light conversion efficiency corresponding to the incident pump light is 31.7%, when the frequency
is gradually increased from 130 kHz. When the output is reduced, the output power and
conversion efficiency are gradually reduced. When the modulation is 90 kHz, 50 kHz and 20 kHz,
respectively, the maximum gain is 5.8 W.
The laser output of 5.2W and 3.2W, the corresponding light and light conversion efficiencies
are 32.2%, 26% and 17.7%, respectively. It can be seen that the Nd:YVO4 intracavity frequency
doubling laser pumped at 914nm is able to operate at high repetition rate. A relatively high
conversion efficiency is obtained. For a case where the repetition frequency is relatively low,
especially at a frequency of 20 kHz, the output power will have a similar thermal saturation effect
as the pump power increases. After the pump power exceeds 14 W, the output power is The slope
is obviously declining. Our analysis is mainly because the high-doping concentration crystal is
more serious when the inverter is running at low frequency, because the up-conversion rate can be
written as n2.
Where is the up-conversion coefficient, n is the inverse particle number density [12-16],
from which we can see that the up-conversion rate is proportional to the square of the inverse
particle number density, especially in the high When the doping concentration crystal is operated
at a low frequency and the pump power is high, the number density of the inverted particles is
high at this time, and the up-conversion and fluorescence quenching effects are further enhanced,
so that the light-to-light conversion rate is significantly lowered.
7. 8
20kHz
50kHz
6
90kHz
130kHz
170kHz
4
2
0
0 2 4 6 8 10 12 14 16 18 20
Incidence pump power (W)
Fig 3 Relationship between output power and pump power at different repetition rate
8
output pow er
Efficiency for absorbed pump pow er
6
0.8
0.7
0.6
4 0.5
0.4
2
0.3
0
0 20 40 60 80 100 120 140 160 180
Repetition Rate (kHz)
0.2
Fig 4 Relationship between output power , efficiency and repetition frequency
at pump power of 18W
Outputpowerof532nmOutputpower(W)
Efficiencyat.%
8. Figure 4 shows the output power, light-to-light conversion efficiency (corresponding to
absorbed pump power) and repetition frequency for 18W pump power.
Relationship, it can be seen from the experimental results that when the repetition frequency is
gradually increased from 40 kHz to 130 kHz, the output power is also increased, and the light-to-
light conversion efficiency is also slowly increased. When the repetition frequency is 130 kHz, the
output power is up to 6.7 W. When the frequency is gradually increased from 130kHz to 170kHz,
the output power decreases. When the modulation frequency is 170kHz, the output power drops to
5.7W, but the output power and light-to-light conversion efficiency of the above two processes are
slowly changing, but when When the repetition frequency is reduced from 30 kHz to 15 kHz, both
the output power and the light-to-light conversion efficiency drop sharply. Experimental results
show that this
The 914nm resonant pumped high-doped Nd:YVO4 laser is more suitable for operation at high
repetition frequency. When the repetition frequency is too low, the high-doped crystal has a short
upper energy level lifetime and a high up-conversion coefficient, which leads to strong
spontaneous emission. And upconversion loss.
The experimental measurement shows that the pulse width is 52 ns at a pulse frequency of 130
kHz, and the corresponding peak power is 1 kW. We measure the beam quality of the laser with a
knife edge (90/10), and obtain the beam quality factor of the green light in the X direction and the
Y direction. The results are 1.3 and 1.2, respectively. The measurement results are shown in
Figure 5. The reason why the better beam quality output can be obtained is mainly because: First,
the 914nm pump reduces the heat generated by the quantum loss, thereby reducing the thermal
lens effect. The beam quality is improved; secondly, reasonable pattern matching is also an
important reason for obtaining good beam quality.
10. 4. Conclusion
For the first time, the 914nm resonant pumping technology is applied to the acousto-optic Q-
switched intracavity frequency doubling laser. In the experiment, Nd:YVO4 is used as the gain
medium, and the class I critical phase matching LBO is used as the frequency doubling crystal.
High repetition rate, high beam quality 532nm laser output. The laser has good performance at
high repetition frequency. When the repetition frequency is low (<30kHz), the doping
concentration of Nd:YVO4 is high, especially when high power pumping is up-converted and
spontaneous emission is compared. Serious, it will lead to a significant decline in light and light
conversion efficiency. When the pump power is 18W and the repetition frequency is 130kHz, the
multiplier light output of up to 6.7W is obtained, the light-to-light conversion rate corresponding
to the incident pump light is 37.2%, and the light-to-light conversion rate corresponding to the
absorbed pump light is 60%. The conversion efficiency can reach the level compared with the
traditional 808nm pumping method, and has a good application prospect.
References
[1] Zhao J T,Feng G Y, Yang H M, et al. Analysis of thermal effect and its
influence on output power of thin disk laser[J]. Acta Physica Sinica, 2012, 61(8):
084208
[2] Lavi R,Jackel S. Thermally boosted pumping of neodymium Lasers[J]. Applied
Optics, 2000,39(18):3093-3098
[3] Sato Y, Taira T, Pavel N et al. Laser operation with near quantum-defect slope
efficiency in Nd:YVO4 under direct pumping into the emitting level[J]. Applied
Physics Letter, 2003,82(6):844-846.
[4] McDonagh L, Wallenstein R, Knappe R. High-efficiency 60W TEM00 Nd:YVO4
oscillator pumped at 888nm[J]. Optics Letter ,2006,31(22):3297-3299
[5] Zhu P, Li D J, Hu P X et al. High efficiency 165W near diffraction limited
Nd:YVO4 slab oscillator pumped at 880 nm[J]. Optics Letter ,2008,33(17):1930-1932
[6] Ding X, Yin S J, Shi C P et al. High efficiency 1342nm Nd:YVO4 laser in-band
pumped at 914 nm[J].Optics Express,2011, 19(15):14315-14320
[7] Hong H L, Huang L, Liu Q et al. Compact high-power, TEM00 acousto-optics Q-
switched Nd:YVO4 oscillator pumped at 888 nm[J]. Applied Optics, 2012,51(3): 323-
327
[8] Sangla D, Castaing M, Balembois F et al. Highly efficient Nd:YVO4 laser by
direct in-band diode pumping at 914nm[J]. Optics Letter, 2009,34(14): 2159-2161
[9]Chen M, Chang L, Yang C et al. 100 kHz Nd:YVO4 Picosecond regenerative
amplifier end-pumped by 914 nm laser Diode[J]. Chinese Journal of Lasers, 2013,40(6):
0602010
[10] Ding X, Zhang H Y, Sheng Q, et al. High efficiency Nd:YVO4 laser in-band
11. pumped from high Stark level of ground state at 914nm[J]. Chinese J. Lasers 2013,
40(7): 0702008
[11] Tanant W, Arkady M. High efficiency passively mode-locked Nd:YVO4 laser
with direct in-band pumping at 914 nm[J]. Optics Express, 2016,24(12):12851-12855
[12] Ostroumov V, Jensen T, Meyn J P, et al. Study of luminescence concentration
quenching and energy transfer upconversion in LaSc3e(BO3)4 and GdVO4 laser
crystals[J]. Journal of Optics Society America B, 1998,15(3), 1052–1060.
[13] Laurent M, Gilles P , Gerald R. Determination of the energy diffusion and the
Auger upconversion constants in a Nd:YVO4 standing wave laser[J]. Optics
Communications, 2002,203: 341–347.
[14] Guy S, Bonner C L, Shepherd D P, et al. High-inversion densities in Nd:YAG:
upconversion and bleaching[J]. IEEE Journal of Quantum Electron. 1998.34(5), 900–
909.
[15] Chen Y F, Liao C C, Lan Y P et al. Determination of the Auger upconversion
rate in fiber-coupled diode endpumped Nd:YAG and Nd:YVO4 crystals[J] Applied
Physics B. 2000, 70:487–490.
[16] Délen X, Balembois F, Musset O et al. Characteristics of laser operation at 1064
nm in Nd:YVO4 under diode pumping at 808 and 914 nm[J]. Journal Optics Society
America B, 2011,28(1):52-57 .