The document discusses the history and opportunities of optoelectronics. It begins with early pioneers like Oleg Losev who discovered LEDs in the 1920s. Semiconductor LEDs and lasers are now common in everyday devices. Applications discussed include flat panel displays, vehicle lighting, healthcare technologies like photodynamic therapy, and high-speed data communications. Lasers enable applications from corrective eye surgery to weapons decommissioning. Overall, optoelectronics has transformed modern technology and its study is important for 21st century education.
This lecture is based on post-graduate students of Ophthalmology (DO, DCO, MCPS, FCPS, MS) and optical principle of LASER, construction of laser and laser tissue interaction has cover the lecture
This lecture is based on post-graduate students of Ophthalmology (DO, DCO, MCPS, FCPS, MS) and optical principle of LASER, construction of laser and laser tissue interaction has cover the lecture
The attached narrated power point presentation mentions the different types of optical sources used for optical fiber communications, the requirements for light sources for optical fiber communications, direct and indirect bandgap semiconductors and different types of LEDs in use today along with their comparison. The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
A p-n junction diode which emits spontaneous emission of radiation in the visible and IR regions when forward biased is called Light Emitting Diode.
This converts the input electrical energy into optical energy in the visible or IR spectrum depending on the semiconductor material
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Optical fiber communication Part 2 Sources and DetectorsMadhumita Tamhane
For optical fiber communication, major light sources are hetero-junction-structured semiconductor laser diode and light emitting diodes. Heterojunction consists of two adjoining semiconductor materials with different bandgap energies. They have adequate power for wide range of applications. Detectors used are PiN diode and Avalanche Photodiode. Being very small in size and feeding to small core optical fiber, it is very important to study emission characteristics of sources and their coupling to fiber. As it can operate for low power over a long distance, received power is very small, hence study of noise characteristics of detectors is very essential...
The attached narrated power point presentation mentions the different types of optical sources used for optical fiber communications, the requirements for light sources for optical fiber communications, direct and indirect bandgap semiconductors and different types of LEDs in use today along with their comparison. The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
A p-n junction diode which emits spontaneous emission of radiation in the visible and IR regions when forward biased is called Light Emitting Diode.
This converts the input electrical energy into optical energy in the visible or IR spectrum depending on the semiconductor material
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Optical fiber communication Part 2 Sources and DetectorsMadhumita Tamhane
For optical fiber communication, major light sources are hetero-junction-structured semiconductor laser diode and light emitting diodes. Heterojunction consists of two adjoining semiconductor materials with different bandgap energies. They have adequate power for wide range of applications. Detectors used are PiN diode and Avalanche Photodiode. Being very small in size and feeding to small core optical fiber, it is very important to study emission characteristics of sources and their coupling to fiber. As it can operate for low power over a long distance, received power is very small, hence study of noise characteristics of detectors is very essential...
Transparent electronics is an emerging science and technology field concentrates on producing ‘invisible’ electronics circuit and optoelectronics devices. The application contains consumer electronics such as automobile windshield, transparent solar panel, transparent display and real time wearable display. In the conventional Si/III-V based electronics, the structure is based on semiconductor junction & transistor. However, the basic building material for transparent electronic devices which is to be transparent and in visible range is a true challenge. Therefore, to understand and implement such technology there are two scientific goals, to have a material which are optically transparent and electrically conductive and to implement an invisible circuitry. Development of such invisible transparent electronic devices needs expertise together from pure and applied science, material science, chemistry, physics &electronic science.
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.
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.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
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.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
1. Optoelectronics: the opportunity
- optoelectronics has come of age!
This perspective is reproduced from a presentation given at an
inauguration mini-symposium on the Optoelectronics College
held in November 2007 at the Ballathie House Hotel .
Professor Wilson Sibbett, University of St Andrews
2. Introductory remarks
• Electronic devices are all around us but what about devices that exploit
‘optoelectronics’?
• Everyday optoelectronic technologies range from flat-screen displays (TVs,
computers, mobile phones …) through the checkout bar-scanners to internet
communications links
• A growing number of healthcare-related implementations of optoelectronics are
beginning to emerge in biology and medicine
• In Scotland, we have notable research strengths in optoelectronics and efforts are
being made to translate these into more widespread and practical applications
3. Basis of this overview
• Let us start with an historical perspective on optoelectronics
• Then, consider semiconductor devices as the bridge between
electronics and optoelectronics
• Starting with LEDs we proceed to lasers
• We can consider the translation of science to technology
• We can look at a few representative applications of optoelectronics
• All of this has implications for the teaching of optoelectronics
4. Oleg Vladimirovich LOSEV –
the short life of a genius
• We must acknowledge the early work
of pioneer, Dr Oleg Losev (1903-1942)
• He was the son of a Russian Imperial
Army Officer but the politics of the day
denied him any career path in Bolshevik
Russia!
• Sadly, he died of hunger at the age of 39
during the blockade of Leningrad!
5. Oleg Losev –
the discoverer of the LED?
• He was remarkable as self-educated scientist. His PhD degree was awarded in 1938 by the
Ioffe Institute (Leningrad) without a formal thesis because he had published 43 journal papers
and 16 patents.
• Working in a besieged Leningrad (1941), he discovered that a 3-terminal semiconductor
device could be constructed to have characteristics similar to those of a triode valve but
circumstances prevented publication! Losev had probably invented the TRANSISTOR!
• Mid-1920s: Oleg Losev observed light emission from electrically-biased zinc oxide and silicon
carbide crystal rectifier diodes – Light Emitting Diodes or LEDs!
• Called the “inverse photo-electric effect”, Losev worked out the theory of LED operation and
studied the emission spectra and even observed spectral narrowing at high drive currents –
evidence perhaps of the stimulated emission that applies to lasers?!
• Notably, the first significant blue LED re-invented in the 1990s used silicon carbide!!
6. Semiconductor LEDs and lasers
• LEDs are now commonplace in games consoles, remote controls, vehicle lights,
traffic lights and, increasingly, in domestic lighting
• By the end of this decade, the market value is predicted to reach $15B!
• Semiconductor lasers: the LED process is at the core of this effect and laser action
was first reported in 1962 by four US research groups (2 at GE, IBM, MIT)
• The are many everyday applications of semiconductor lasers in barcode readers,
CD & DVD players, optical-carrier sources for communications and internet data
• NB: The optical frequency for the optimum telecommunications wavelength
(~1500nm) is extremely high - equivalent to ~200 THz (i.e. 200,000,000,000,000Hz)!
7. Major areas of commercial growth in the
optoelectronics marketplace
• Flat-panel displays: recorded sales are up 30% year on year: currently,
8% growth in Europe & USA and 9% in Japan
• Solid-state vehicle lighting: much more than just brake lights!
• Solid-state domestic lighting: replacement of incandescent lighting with
LED-based sources would reduce CO2 emissions by many millions of
tonnes worldwide!
• Power generation: solar cell technologies are progressing steadily – for
example, in Germany a new power station based on solar cells is
producing 5MW to power up 1800 households
8. Recent advances in LEDs for domestic
lighting
By way of background:
• Incandescent lights are not efficient and have a so-called luminous
efficacy of 13-14 lumens/Watt (L/W)
• Halogen lighting is a little more efficient at 17L/W
• Fluorescent lights are significantly better with typical luminous efficacies
of 60-70L/W
More recently:
• White LEDs have achieved 100L/W and, in the laboratory, figures up to
300L/W have been reported for tailored ‘warm-white’ LED lighting!
9. Organic semiconductors
• We can now have organic
materials that have exploitable
semiconducting characteristics.
These feature:
• Conjugated molecules
• Novel types of semiconductors
• Easy processing schemes
• LED compatibility
• Physical flexibility
10. Organic light emitting diodes (OLEDs)
These diagrams illustrate the basic OLED concepts.
11. Examples of some OLED displays
Sony ultra-thin 13” display
Kodak viewfinder
Epson widescreen display
12. Photo-dynamic therapy (PDT)
The ‘sensitised’ tumour
region is then exposed to
intense light from a
source such as a laser or
LED
Exposure to light induces
the PP9 to produce singlet
molecular oxygen that leads
to local cell kill within the
tumour
ALA* cream is applied to the
site of the skin tumour
(*5-aminolevulinic acid)
The ALA is metabolised to light-sensitive
PP9 predominantly within the tumour
13. Before After
A typical scar-free outcome from photo-
dynamic therapy or ‘PDT’ of a skin cancer
14. Potential of OLEDs for PDT
OLEDs have the advantages of:
• Uniform illumination
• Light weight – so can be worn
• Relatively low intensity for longer treatment
– So reduced pain, increased effectiveness
• Low cost - disposable
– Attractive for hygiene
– Widens access to PDT
• A simple wearable power supply
• Ambulatory treatment1
– At work
– At home
1. See for example, Moseley et al, Brit.Jour.Derm., 154, 747 (2006)
16. Skin cancer treated with OLED-based PDT
Effective treatment with reduced scarring and pain
17. Concept of spontaneous emission
Level 1
Energy = E1
Level 2
Energy = E2
• Consider an ‘excited’ atom
• This excited atom will relax
over some characteristic
relaxation time
• If photons are produced during
the relaxation process this is
called spontaneous emission
• This emission process is
independent of external
influences
18. Concept of stimulated emission
• An excited atom can be stimulated to emit a photon
• This process is called stimulated emission
• The stimulated photon is an exact copy of the photon that induced the transition
• A repeat of this process leads to the optical gain which represents the basis of laser
action
Excited Atom
Incident
Photon
Stimulated Transition Incident Photon
Emitted
Photon
19. • Stimulated emission provides optical gain
• Photons reflected by the resonator mirrors cause an avalanche of stimulated
emission along the axis of the resonator
• A high intensity beam of light thus builds up in the laser resonator
• A collimated and directional laser beam emerges from a partially transmitting
exit mirror
A laser or ‘laser oscillator’
20. A semiconductor diode laser chip
200nm active
GaAs layer
3mm p-type GaAlAs
n-type GaAlAs
~200mm
• Cleaved or cleaved-and-coated facets act as the mirrors in a
diode laser
• This is the preferred source for optical communications
22. Illumination of a hand and wrist area with light in 700nm, 800nm,
900nm spectral regions illustrates clearly the deeper penetration at
the longer wavelengths into the biological tissue
23. Treatment of varicose veins
• The laser used produces green pulses of light for strong
absorption in blood but having durations matched to the tissue
thermal relaxation time.
Before After
24. Skin resurfacing using lasers
• Laser skin resurfacing is becoming the method of choice
– preferable to chemical peels or dermabrasion
• A pulsed carbon dioxide laser is used
Before After!
25. We can now consider “digital optoelectronics”
• Lasers can be made to produce either:
- constant intensity beams, or
- sequences of discrete optical pulses or “optical digits”
Pulsed
Continuous
Time
Intensity
26. Why might we wish to use optical digits?
• The laser pulses or ‘optical digits’ can have very high peak intensity
• Thus, these light ‘impulses” can induce either single- photon or rather more
interesting multiple-photon interactions
• The advantage is strong near-infrared absorption (in tissue) with interactions
involving two or three photons that are equivalent to green or blue/uv light
• The average power or heating effect can be at a modest level to avoid tissue
damage
• Ultrashort pulses [picoseconds (10-12s) and femtoseconds (10-15s)] also imply
short exposure times and so we have ultrafast (or snapshot) photography
27. An example of a multiple-photon excitation
• This multi-photon excitation is localised both in space and in time
- interactions occur primarily at the beam focus for the ultrashort light pulses
- penetration of long-wavelength light but interaction may involve 2,3 photons!
28. Multi-photon excitation for treatment of
cancer tumours (PDT)
Photogen Inc, Knoxville Tennessee & Massachusetts Eye & Ear Infirmary
For example: Melanoma on skin in mice
The laser pulses are in the near-infrared (1047nm) but 3-photon
absorption is exploited for the photo-dynamic therapy (PDT)
Prior to treatment Immediately following
treatment
2 months after
treatment
29. Snapshots in the millisecond regime
[Eadweard Muybridge –Galloping Horse, 1887]
30. Flash photography with microsecond exposures
• The motion can be effectivelt ‘frozen’ using short pulses of light
- e.g., using 1 microsecond flashes from a xenon flashbulb
31. An example of ‘frozen motion’!
[Harold Edgerton, MIT, 1964]
32. Concept of prompt imaging
• An ultrashort laser pulse passing through a scattering medium
carries image information via three components as illustrated
Input
diffuse
snake-like ballistic
snake-like
ballistic
diffuse Output
33. Seeing through raw chicken!
Photograph of two
crossed metal needles
(0.5mm diameter)
The needles viewed
through a 6mm slab of raw
chicken breast in ordinary
illumination
‘Snapshot’ image of the
needles using
femtosecond illuminating
and gating pulses
34. Laser beam propagation in optical fibres –
many-km-lengths of glass!
• Intensity
– either continuous or pulsed
• Focusability
– efficient coupling & propagation of laser beams in optical fibres
Many applications in endoscopy and tele/data-communications
Optical fibre
37. Optoelectronic datacomms at 100Tb/s!
What data speed does this represent?
100 Tbits ~1.5x1012 words ~1.7 million x
works of Shakespeare -
in one second!
38. High-speed data transfer - DVDs
Other information media?
100 Tbits > 600 DVD
movies!!
in one second
40. Corrective eye surgery using laser pulses
Schematic of a laser-pulse produced flap:
– laser pulses focused 160µm below the tissue surface to
produce micro-cavitations
– subsequent micro-machined cut to provide hinged flap
41. Femtosecond laser-based eye surgery
Femtosecond-laser-based Keratomileusis procedure
– Laser pulses are focused and scanned to outline with micron precision a
lens-shaped block of corneal stroma or lenticule
– This lenticule is then removed and the corneal flap replaced
42. Optoelectronics for peace – weapons
decommissioning!
• Femtosecond laser pulses cut pellets of high-explosive and metals
F Roeske Jr et al
Cut in HNS (LX-15) with
femtosecond laser pulses
Cut in PETN (LX-16) with
500ps laser pulses
KEY ADVANTAGES
- this process offers a high safety status
- there are no solid HE waste products
- this offers decommissioning opportunities!
43. Concluding remarks
• Optoelectronic devices have come of age and have opened up a wide range of
exciting possibilities both within science and in the products used in everyday
life
• These are re-defining many of the boundaries of modern life and technology
• Some knowledge of optoelectronics is vital for all of us living in the 21st
century
• It follows, therefore, that the teaching of some practical skills in
optoelectronics should now form an ‘exciting’ part of a modern
science curriculum and education!