(A) By active media
Solid state laser - crystal, or glass, doped with impurities, e.g. ruby laser, Ti:sapphire laser, semiconductor laser.
Gas laser - e.g. He-Ne laser, Ar+ laser, CO2 laser, N2 laser, HCN laser.
Dye laser - active medium: dye molecules in liquid solvent (sometimes in solids also).
(B) By mode of operation
CW
Pulsed
(C) By pumping and laser levels
3-level laser
4-level laser
This belongs to Physical Chemistry portion and it contains most of
things about laser working and principles.
By Aaryan Tyagi's Group
M.Sc. Applied Chemistry (1 Sem)
Amity University, Noida
Light Amplification by Stimulated Emission of Radiation. Its basic principle of working, features or characteristics, types, applications, hazards caused by LASER and future scopes.
Laser science is principally concerned with quantum electronics, laser construction, optical cavity design, the physics of producing a population inversion in laser media, and the temporal evolution of the light field in the laser. It is also concerned with the physics of laser beam propagation, particularly the physics of Gaussian beams, with laser applications, and with associated fields such as non-linear optics and quantum optics.
This belongs to Physical Chemistry portion and it contains most of
things about laser working and principles.
By Aaryan Tyagi's Group
M.Sc. Applied Chemistry (1 Sem)
Amity University, Noida
Light Amplification by Stimulated Emission of Radiation. Its basic principle of working, features or characteristics, types, applications, hazards caused by LASER and future scopes.
Laser science is principally concerned with quantum electronics, laser construction, optical cavity design, the physics of producing a population inversion in laser media, and the temporal evolution of the light field in the laser. It is also concerned with the physics of laser beam propagation, particularly the physics of Gaussian beams, with laser applications, and with associated fields such as non-linear optics and quantum optics.
Energy scenario in india and its energy conservation programJyoti Singh
Energy is essential for Economic growth and economic growth is essential for country like India.
Ratio of energy demand and GDP is useful indicator for Economics growth.
Economic growth of country
is depend upon rate of
improvement in per capita
energy consumption.
India is both a major producer and consumer.
India currently ranked 11th greatest energy producer accounting 2.4% of world’s total energy production and as the world’s 6th greatest energy consumer.
Despite its large annual energy production, India is a net energy importer, mostly due to imbalance between oil production and consumption.
The utility electricity sector in India had an installed capacity of 278.734 GW as of 30 September 2015. Renewable Power plants constituted 28% of total installed capacity and Non-Renewable Power Plants constituted the remaining 72%.
During the year 2014-15, the per capita electricity generation in India was 1,010 kWh with total electricity consumption (utilities and non utilities) of 938.823 billion or 746 kWh per capita electricity consumption.
Electric Energy Consumption in agriculture was recorded highest (18.45%) in 2014-15 among all countries.
The optical and infrared spectroscopy industry is undergoing a major transformation akin to the computer industry. The
size and weight of the instruments are shrinking from bench-top size to pocket-size. The cost is decreasing, and the
performance continues to improve beyond just being acceptable. These miniature handheld spectrometers such as near
infrared (NIR) spectrometers are creating new populations of users taking measurements in the field by nontechnical
workers that were previously conducted in the laboratory by technical personnel. The tests are non-destructive and fast,
taking only a few seconds to complete. This capability allows for obtaining real-time results that, in turn, lead to more
efficient decision making. Users include farmers who would use their handheld NIR analyzers for a whole host of
applications from analyzing the nutritional content of their forage for animal feed optimization to analyzing the
nutritional content of their crop for determining the value of their yield, or for analyzing the soil for fertilization
optimization.
Standard Soil Testing Laboratory
time consuming, Laborious, use of chemical and reagents which effect human health and environment, costly, do not consider spatial variation in the field.
Electrochemical Sensing
Ion Selective Electrodes
Ion Sensitive Field Effect Transistor
Optical Spectroscopy
NIR Spectroscopy
Conversion of transfer function to canonical state variable modelsJyoti Singh
Realization of transfer function into state variable models is needed even if the control system design based on frequency-domain design method.
In these cases the need arises for the purpose of transient response simulation.
But there is not much software for the numerical inversion of Laplace transform.
So one ways is to convert transfer function of the system to state variable description and numerically integrating the resulting differential equations rather than attempting to compute the inverse Laplace transform by numerical method.
A basic sound system consists of an input device (microphone), a control device (mixer), an amplification device (power amplifier), and an output device (loudspeaker).
The primary goal of the sound system in sound applications is to deliver clear, intelligible speech, and, usually, high-quality musical sound.
Chopper basically uses a Thyristor for high power applications. The process of turning off a conducting Thyristor is known as commutation. Here Thyristor is turned off by a current pulse that is why it is called a Current Commutated Chopper.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
HEAP SORT ILLUSTRATED WITH HEAPIFY, BUILD HEAP FOR DYNAMIC ARRAYS.
Heap sort is a comparison-based sorting technique based on Binary Heap data structure. It is similar to the selection sort where we first find the minimum element and place the minimum element at the beginning. Repeat the same process for the remaining elements.
An Approach to Detecting Writing Styles Based on Clustering Techniquesambekarshweta25
An Approach to Detecting Writing Styles Based on Clustering Techniques
Authors:
-Devkinandan Jagtap
-Shweta Ambekar
-Harshit Singh
-Nakul Sharma (Assistant Professor)
Institution:
VIIT Pune, India
Abstract:
This paper proposes a system to differentiate between human-generated and AI-generated texts using stylometric analysis. The system analyzes text files and classifies writing styles by employing various clustering algorithms, such as k-means, k-means++, hierarchical, and DBSCAN. The effectiveness of these algorithms is measured using silhouette scores. The system successfully identifies distinct writing styles within documents, demonstrating its potential for plagiarism detection.
Introduction:
Stylometry, the study of linguistic and structural features in texts, is used for tasks like plagiarism detection, genre separation, and author verification. This paper leverages stylometric analysis to identify different writing styles and improve plagiarism detection methods.
Methodology:
The system includes data collection, preprocessing, feature extraction, dimensional reduction, machine learning models for clustering, and performance comparison using silhouette scores. Feature extraction focuses on lexical features, vocabulary richness, and readability scores. The study uses a small dataset of texts from various authors and employs algorithms like k-means, k-means++, hierarchical clustering, and DBSCAN for clustering.
Results:
Experiments show that the system effectively identifies writing styles, with silhouette scores indicating reasonable to strong clustering when k=2. As the number of clusters increases, the silhouette scores decrease, indicating a drop in accuracy. K-means and k-means++ perform similarly, while hierarchical clustering is less optimized.
Conclusion and Future Work:
The system works well for distinguishing writing styles with two clusters but becomes less accurate as the number of clusters increases. Future research could focus on adding more parameters and optimizing the methodology to improve accuracy with higher cluster values. This system can enhance existing plagiarism detection tools, especially in academic settings.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
NUMERICAL SIMULATIONS OF HEAT AND MASS TRANSFER IN CONDENSING HEAT EXCHANGERS...ssuser7dcef0
Power plants release a large amount of water vapor into the
atmosphere through the stack. The flue gas can be a potential
source for obtaining much needed cooling water for a power
plant. If a power plant could recover and reuse a portion of this
moisture, it could reduce its total cooling water intake
requirement. One of the most practical way to recover water
from flue gas is to use a condensing heat exchanger. The power
plant could also recover latent heat due to condensation as well
as sensible heat due to lowering the flue gas exit temperature.
Additionally, harmful acids released from the stack can be
reduced in a condensing heat exchanger by acid condensation. reduced in a condensing heat exchanger by acid condensation.
Condensation of vapors in flue gas is a complicated
phenomenon since heat and mass transfer of water vapor and
various acids simultaneously occur in the presence of noncondensable
gases such as nitrogen and oxygen. Design of a
condenser depends on the knowledge and understanding of the
heat and mass transfer processes. A computer program for
numerical simulations of water (H2O) and sulfuric acid (H2SO4)
condensation in a flue gas condensing heat exchanger was
developed using MATLAB. Governing equations based on
mass and energy balances for the system were derived to
predict variables such as flue gas exit temperature, cooling
water outlet temperature, mole fraction and condensation rates
of water and sulfuric acid vapors. The equations were solved
using an iterative solution technique with calculations of heat
and mass transfer coefficients and physical properties.
1. TYPES OF LASERSubmitted to: Submitted
by:
Mrs Yogendra Narayan Jyoti Singh
Research Scholar (EE Dept) ME (
Regular)
NITTTR, Chandigarh I & C 2nd Sem
Roll No: 142511
2. Types of Laser
(A) By active media
Solid state laser - crystal, or glass, doped with
impurities, e.g. ruby laser, Ti:sapphire laser,
semiconductor laser.
Gas laser - e.g. He-Ne laser, Ar+ laser, CO2 laser, N2
laser, HCN laser.
Dye laser - active medium: dye molecules in liquid
solvent (sometimes in solids also).
(B) By mode of operation
CW
Pulsed
(C) By pumping and laser levels
3-level laser
4-level laser
3. Solid State Lasers: General
properties
Solid state lasers use high density solid media
as active laser materials.
Ions of transition elements, particularly rare
earth elements (Nd, Yb, Er, Ho etc.) or transition
metals (Cr, Ti etc.) are used most commonly as
dopants.
Host materials include crystals like sapphire
(Al2O3), YLF (YLiF4), YAG (Y3Al5O12), LISAF
(LiSrAlF6), LICAF (LiCaAlF6), as well as glasses
from silicate (SiO2) and phosphate (P2O5)
classes.
7. Advantages
No chance is of wasting material in the active
medium because here material used is in solid
form not in gas form, where this occurs.
Both continuous and pulsed output is possible
from solid state lasers.
Solid state lasers have high
Construction is comparatively simple.
Output power ranging from very low value of
about 0.04 watts to high value of about 600
watts.
Cost of solid state lasers is economical.
8. Disadvantages
Efficiency of solid state laser is very low as
compared to CO2 lasers.
Great disadvantage of solid state lasers is the
divergence, which is not constant and ranges
1 milli radian to 20 milli radian.
Output power is also not very high as in CO2
lasers.
Due to thermal lasing in solid state lasers, the
power loss occurs when the rod gets too hot.
9. Applications / Uses of Solid state
Lasers
Nd: YAG solid state lasers usually used when
drilling holes in metals.
Nd: YAG pulsed type solid state lasers can be
used in medical applications such as in
endoscopy etc.
As military application, Nd:YAG is used by
target destination system.
10. Ruby Laser
Ruby laser is the first working laser
demonstrated by Ted Maiman.
Host material is corundum (Al2O3) crystal,
dopants are Cr ions.
Lasing Wavelength is 694 nm.
Pumping is done with flash lamps and laser
operates in pulsed regime.
13. Advantages of Ruby Lasers
From cost point of view, the ruby lasers are
economical.
Beam diameter of the ruby laser is
comparatively less than CO2 gas lasers.
Output power of Ruby laser is not as less as in
He-Ne gas lasers.
Since the ruby is in solid form therefore there is
no chance of wasting material of active
medium.
14. Disadvantages of Ruby Laser
In ruby lasers no significant stimulated
emission occurs, until at least half of the
ground state electrons have been excited to
the Meta stable state.
Efficiency of ruby laser is comparatively low.
Optical cavity of ruby laser is short as
compared to other lasers, which may be
considered a disadvantage.
15. Applications
One of the first applications for the ruby laser
was in range finding.
Due to low output power they are class-I lasers
and so may used as toys for children’s.
It can be used as decoration piece & artistic
display.
16. Semiconductor Laser
The semiconductor laser is very small in size
and appearance.
It is similar to a transistor and has the
operation like LED but the output beam has
the characteristics of laser light.
The material which often used in
semiconductor laser is the gallium Arsenide,
therefore semiconductor laser is sometimes
known as Gallium Arsenide Laser.
It is also called Injection Laser.
18. Advantages of Semiconductor
Lasers
Smaller size and appearance make them good
choice for many applications.
From cost point of view the semiconductor
lasers are economical.
Semiconductor lasers construction is very
simple.
No need of mirrors is in semiconductor lasers.
Semiconductor lasers have high efficiency.
The low power consumption is also its great
advantage.
19. Disadvantages of Semiconductor
Lasers
Semiconductor laser is greatly dependent on
temperature. The temperature affects greatly
the output of the laser.
The lasing medium of semiconductor lasers is
too short and rectangular so the output beam
profile has an unusual shape.
Beam divergence is much greater from 125 to
400 milli radians as compared to all other
lasers.
The cooling system requirement in some
cases may be considered its disadvantage.
20. Application/Uses of Semiconductor
Lasers
The semiconductor laser can be pulsed at
varying rate and pulse widths. Therefore this
laser is a natural transmitter of digital data.
Semiconductor laser is well suited for interface
with fiber optic cables used in communication.
21. Gas Laser
Gas lasers are widely available in almost all
power (milli watts to megawatts) and
wavelengths (UV-IR) and can be operated in
pulsed and continuous modes.
Gas lasers use low density gaseous materials
as active media.
Electrical pumping (continuous, RF or pulsed)
is used.
The gas lasers can be made from neutral
atoms (He-Ne, metal vapor etc), ions (e.g. Ar+)
or molecules (e.g. CO2).
22. He-Ne Laser
The He-Ne laser active medium consists of
two gases which do not interact form a
molecule. Therefore He-Ne laser is one type of
atomic gas lasers.
The gain medium consists of a mixture of
helium and neon (10:1) inside of a small bore
capillary tube, usually excited by a DC
electrical discharge.
25. Advantages of He-Ne Laser
He-Ne laser has very good coherence property.
He-Ne laser can produce three wavelengths that
are 1.152µm, 3.391 µm and 632.8nm, in which
the 632.8nm is most common because it is visible
usually in red color.
He-Ne laser tube has very small length
approximately from 10 to 100cm and best life time
of 20.000 hours.
Cost of He-Ne laser is less from most of other
lasers.
Construction of He-Ne laser is also not very
complex.
He-Ne laser provide inherent safety due to low
26. Disadvantages of He-Ne
Laser
It is relatively low power device means its output
power is low.
He-Ne laser is low gain system/ device.
To obtain single wavelength laser light, the other
two wavelengths of laser need suppression, which
is done by many techniques and devices. So it
requires extra technical skill and increases the
cast also.
High voltage requirement can be considered its
disadvantage.
Escaping of gas from laser plasma tube is also its
disadvantage.
27. Applications / Uses of He-Ne
Laser
The Helium-Neon gas laser is one of the most
commonly used laser today because of the
following applications.
He-Ne lasers are produced in large quantities
from many years.
He-Ne lasers also used in super market checkout
counters to read bar codes and QR codes.
The He-Ne lasers also used by newspapers for
reproducing transmitted photographs.
He-Ne lasers can be use as an alignment tool.
It is also used in Guns for targeting.
28. Ion Laser: Argon Ion Laser
All ion lasers (such as argon, Krypton and mix
gas) produce several different wavelengths so
they are designed to produce these
wavelengths either simultaneously or
individually.
Argon lasers are generally operated in
continuous wave mode.
For argon lasers the output power can ranges
from few mill watts up to 20 watts.
31. Advantages of Argon Laser
Production of multiple wave lengths is the
main advantage plus characteristic of argon as
well as other ion lasers.
Argon lasers produce high power output as
compared to He-Ne laser.
Argon laser is a higher gain system.
Argon laser like He-Ne has very less
divergence, typically about 1 milli radian
32. Disadvantages of Argon laser
The overall efficiency of argon laser is very
less usually lies between 0.01% and 0.1%.
Large amount of power requirement is also its
disadvantage.
Construction is very difficult.
Cost of argon laser is not as low as He-Ne
laser.
Power supply of high voltages required,
because due to solenoid there is extra burden
on it.
33. Applications of Argon Laser
Argon lasers used in scientific research.
Argon lasers used in medical application.
An artistic displays and light shows also the
argon lasers are used.
34. Molecular Laser
Unlike isolated atoms and ions in atomic and ionic
lasers, molecules have wide energy bands instead of
discrete energy levels.
They have electronic, vibrational, and rotational
energy levels.
Energy separation between electronic energy levels
lies in the UV and visible spectral ranges, while those
of vibrational–rotational (separations between two
rotational levels of the same vibrational level or a
rotational level of one vibrational level to a rotational
level from other lower vibrational level) levels, in the
NIR and far-IR regions.
Therefore, most of the molecular lasers operate in the
NIR or far-IR regions.
35. Carbon Dioxide (CO2) Laser
Therefore CO2 gas laser is considered the type of
molecular gas laser.
Importantly note that CO2 lasers use carbon
dioxide as well as Helium & Nitrogen as its active
medium.
The role of N2 is to facilitate the CO2 pumping &
population inversion process by providing
molecule collision with the CO2 gas.
The role of He is to facilitate the removal of
decayed molecules from their lower energy level
to ground level after lasing process, in order to
maintain the population inversion.
36. CO2 Gas Laser is a high power laser generating device .
The laser light takes place within the molecules of carbon
dioxide
Construction and working of CO2 Gas
Laser
37. The CO2 Gas Laser consist of mixture of gases like O2-N2,
He and
CO2.
Construction and working of CO2 Gas
Laser
38. Construction and working of CO2 Gas
Laser
The CO2 Gas Laser consist of mixture of gases like O2-N2,
He and
CO2.
39. The CO2 Gas Laser consist of mixture of gases like O2-N2,
He and
CO2.
Construction and working of CO2 Gas
Laser
40. Since heat is an undesired byproduct for lasing action in this
type of
lasers, so it always contains a heat exchange system to
remove the
Construction and working of CO2 Gas
Laser
41. The CO2 Gas Laser consists a separate Gas supply system
and the
Blower motor.
Construction and working of CO2 Gas
Laser
42. The Vacuum pump is used to maintain proper Torr level
within the
cavity in order to operate in the state of controlled vacuum.
Construction and working of CO2 Gas
Laser
43. The CO2 Laser contains s series of mirrors in the optical
cavity.
The Rear and Folding mirrors are 100% reflective whereas
Output
Construction and working of CO2 Gas
Laser
44. The folding mirrors are used to lengthen the resonator beam
path to
increase gain/power without physically lengthening the entire
Construction and working of CO2 Gas
Laser
45. The CO2 operates in continuous mode so a shutter devices is
used to
control the output from a CO2 Gas Laser.
Construction and working of CO2 Gas
Laser
46. The CO2 operates in continuous mode so a shutter devices is
used to
control the output from a CO2 Gas Laser.
Construction and working of CO2 Gas
Laser
47. The CO2 Gas Laser consists of more than one anode for the
purpose of maintain even discharge between the anode and
cathode.
By spreading the electrical discharge over a wide area a
Construction and working of CO2 Gas
Laser
51. Advantages of CO2 Laser
In CO2 The CO2 laser offers the lowest cost
per watt along with good beam quality, The
high power levels are obtained ranges from
few watts to 15000 watts.
The efficiency of CO2 gas lasers (i.e. 10% or
higher) is beat than He-Ne and argon lasers.
Long sealed-off lifetime of greater than 20,000
hours.
Small size per watt of output power.
52. Disadvantages of CO2 Laser
Divergence of CO2 lasers approximately in all
cases is greater than He-Ne and Argon laser.
Usually the divergence is ranges from 1 to 10
milli radians.
Beam width varies from 3mm to 100mm.
Some CO2 lasers have the disadvantage of a
short and thick optical cavity.
Cooling system requirement in some
configurations also a disadvantage.
Its cost is comparatively high.
53. Application/Uses of CO2
Lasers
The CO2 gas laser can be used in industry
usually for welding and cutting purposes.
The CO2 laser acts as a surgical tool in the
operating room.
In both energy and weapons research, there is
good field of application of CO2 lasers.
Fractonal C02 Laser Skin Resurfacing
54. Dye Laser (A Liquid Laser)
Liquid lasers are those lasers which uses
liquid as an active medium.
In dye laser the liquid material called dye (for
example rhodamine B, sodium fluoresein and
rhodamie 6G) uses as an active medium,
which causes to produce laser light.
The dye lasers produce output whose
wavelengths are in the visible, ultra violet and
near infrared spectrum.
56. Advantages of Dye Lasers
It is available in visible form (also in non-visible)
Range of wavelengths can be produced by the
using dye lasers.
Beam diameter is very less.
Its beam divergence (0.8 milli radians to 2 milli
radians) is also less from many lasers beam
divergence.
Construction of dye laser is not so complex.
Having the greater efficiency 25%.
High output power is also possible with dye lasers
57. Disadvantages of Dye Lasers
Cost of dye lasers is very high..
To tune at one frequency, the laser uses
birefringent element or filter making it more
costly.
In dye lasers it is very difficult to determine the
element that actually lases because dye has
complex chemical formula.
58. Application of Dye Lasers
Dye lasers are mostly used as a research tool
in medical applications
59. CW and Pulsed Laser
Laser Output as a function of time
From design point of view we can say that
output of all lasers is not constant. Different
types of applications require different types of
lasers. Therefore the output from the laser can
be altered by changing its magnitude over a
period of time
60. Continuous Wave Laser
A laser that are designed to produce a beam of constant
amplitude are called continuous wave or CW lasers. The CW
lasers are rated in power units of watts, milli & kilo watts.
A graph of the power output from the laser as function of time
is shown as:
Since Power = energy / time
or Energy = power X time
Therefore the area below the line in graph represents the
energy transmitted by laser.
61. Pulsed Laser
In normal pulsed laser, the excitation
mechanism is pulsed and the laser is
produced for short time while the pumping
energy is great enough to keep the active
medium above the gain threshold. By diagram
normal pulsed laser can be shown as:
62. Pulsed Laser
Energy curve for normal pulse laser is as
The pulse width for normal
pulsed laser varies from 0.1 to
10 milli seconds.
PRT
The PRT represent the time
for one complete ON-OFF
cycle. This is also referred to
as the period of the pulse
PRT = 1 / PRR