Document
... • The dark current Idark is the current that flows through the detector in the absence of light. • The shot noise is given by 2e( Idark + Isignal). • The noise equivalent power (NEP) is the amount of light at a given wavelength that is equivalent to the noise level of the detector.The noise can be o ...
... • The dark current Idark is the current that flows through the detector in the absence of light. • The shot noise is given by 2e( Idark + Isignal). • The noise equivalent power (NEP) is the amount of light at a given wavelength that is equivalent to the noise level of the detector.The noise can be o ...
File - GENERAL DEPARTMENT
... We call this process spontaneous emission – spontaneous because the event was not triggered by any outside influence. The direction and phase of each of such photons is random. The light from a sodium or mercury lamp is generated in this manner. [Normally, the mean – life of excited atoms before spo ...
... We call this process spontaneous emission – spontaneous because the event was not triggered by any outside influence. The direction and phase of each of such photons is random. The light from a sodium or mercury lamp is generated in this manner. [Normally, the mean – life of excited atoms before spo ...
Photosynthesis Pt 1 Light
... • The colors that you see are the wavelengths that are reflected, not absorbed. • If chlorophyll is a green pigment, then what wavelength is not being absorbed? ...
... • The colors that you see are the wavelengths that are reflected, not absorbed. • If chlorophyll is a green pigment, then what wavelength is not being absorbed? ...
Self-stabilized single-longitudinal-mode operation
... out with 250-p.s square pulses at repetition rates of <100 Hz, corresponding to a 2.5% duty cycle. For longer pump pulse durations, multiple Q-switched pulses have been observed. During operation in a low duty cycle, the transverse mode is confined mainly by the imaginary part of the refractive-inde ...
... out with 250-p.s square pulses at repetition rates of <100 Hz, corresponding to a 2.5% duty cycle. For longer pump pulse durations, multiple Q-switched pulses have been observed. During operation in a low duty cycle, the transverse mode is confined mainly by the imaginary part of the refractive-inde ...
MIT6_007S11_lec50
... Trapping Photons: Mirrors and Waveguides How do we keep photons around for long enough time so they have a chance to stimulate an emission ? ...
... Trapping Photons: Mirrors and Waveguides How do we keep photons around for long enough time so they have a chance to stimulate an emission ? ...
JMacePaper.doc
... excited state, where their numbers quickly build up. So far this is analogous to the threelevel laser. The laser transition then occurs between the second and first excited states, followed by another quick radiationless transition back to the ground state. This type of laser is advantageous because ...
... excited state, where their numbers quickly build up. So far this is analogous to the threelevel laser. The laser transition then occurs between the second and first excited states, followed by another quick radiationless transition back to the ground state. This type of laser is advantageous because ...
Diode pumped distributed Bragg reflector lasers
... In recent years, semiconducting (conjugated) polymers have emerged as an attractive new gain medium for widely tuneable visible lasers [1-6]. Several families of materials have been studied, though much of the work has concentrated on derivatives of poly(paraphenylenevinylene) and poly(fluorene) [4- ...
... In recent years, semiconducting (conjugated) polymers have emerged as an attractive new gain medium for widely tuneable visible lasers [1-6]. Several families of materials have been studied, though much of the work has concentrated on derivatives of poly(paraphenylenevinylene) and poly(fluorene) [4- ...
Optical Sources
... second photon which release two more photons creating an avalanche multiplication. • Amplification &Coherence achieved by (Febry – Perot resonator) • Placing mirrors at either end of the amplifying medium • Providing positive feedback • Amplification in a single go is quite small but after multiple ...
... second photon which release two more photons creating an avalanche multiplication. • Amplification &Coherence achieved by (Febry – Perot resonator) • Placing mirrors at either end of the amplifying medium • Providing positive feedback • Amplification in a single go is quite small but after multiple ...
Pulsed Solid State Laser with Passive Q
... Solid-state lasers (SSL) are lasers based on solid-state gain media such as crystals or glasses doped with rare earth or transition metal ions. Beside fiber lasers they provide one of the most versatile radiation sources in terms of output characteristics when compared to other laser systems. A larg ...
... Solid-state lasers (SSL) are lasers based on solid-state gain media such as crystals or glasses doped with rare earth or transition metal ions. Beside fiber lasers they provide one of the most versatile radiation sources in terms of output characteristics when compared to other laser systems. A larg ...
Tech Notes Wavelength 2012 | www.ll.mit.edu
... Multi-kilowatt-class lasers are used in cutting, welding, and other industrial applications where the high-intensity laser beam is used to locally raise the temperature of the material. These kW-class lasers include CO2, fiber, bulk solid-state lasers, and disk lasers. In the past, individual diode ...
... Multi-kilowatt-class lasers are used in cutting, welding, and other industrial applications where the high-intensity laser beam is used to locally raise the temperature of the material. These kW-class lasers include CO2, fiber, bulk solid-state lasers, and disk lasers. In the past, individual diode ...
Whispering-gallery-mode microdisk lasers
... becomes saturated [The top inset of Fig. 3(a)]. When the pump power intensity exceeds three I th , the output decreases slowly. This is a combination of gain saturation and effect of dye photobleaching. In order to form a stable oscillation in the cavity and make light waves strengthened due to inte ...
... becomes saturated [The top inset of Fig. 3(a)]. When the pump power intensity exceeds three I th , the output decreases slowly. This is a combination of gain saturation and effect of dye photobleaching. In order to form a stable oscillation in the cavity and make light waves strengthened due to inte ...
NewPresentationii22
... • Atoms replace role of the light. • Atom-optical elements replace mirrors and beam splitters ...
... • Atoms replace role of the light. • Atom-optical elements replace mirrors and beam splitters ...
4/10/2006 Chapter 37 Lasers, a Model Atom and Zero Point Energy
... compared to the number of unexcited atoms in a laser? You should think about what would happen to the laser beam if there are more unexcited atoms than excited atoms. How can the atoms in the laser be put into excited states? optical pumping electrical pumping What is a population inversion? What wo ...
... compared to the number of unexcited atoms in a laser? You should think about what would happen to the laser beam if there are more unexcited atoms than excited atoms. How can the atoms in the laser be put into excited states? optical pumping electrical pumping What is a population inversion? What wo ...
Operating Principles
... higher than the amplification gain, the light attenuates. Injected current strengthens amplification gain in an LD and when the gain and the loss are balanced, initial light intensity becomes equal to returned light intensity. This condition is referred to as threshold. A laser oscillates above the ...
... higher than the amplification gain, the light attenuates. Injected current strengthens amplification gain in an LD and when the gain and the loss are balanced, initial light intensity becomes equal to returned light intensity. This condition is referred to as threshold. A laser oscillates above the ...
Physics 123 “Majors” Section Unit 1
... What wavelength do you want the wave to have? What do you want the wave’s amplitude to be? What frequency (or velocity) do you want the wave to have? What do you want the overall phase of the wave to be? ...
... What wavelength do you want the wave to have? What do you want the wave’s amplitude to be? What frequency (or velocity) do you want the wave to have? What do you want the overall phase of the wave to be? ...
Fifty years of laser: world and Latvian experience
... YAG:Nd3+ solid state lasers appeared in the Institute of Physics and Latvian State University mainly for spectroscopic studies, holography and material processing. In 1986, the first picosecond YAG:Nd3+ laser with active mode locking was built in the Institute of Solid State Physics, Latvian State U ...
... YAG:Nd3+ solid state lasers appeared in the Institute of Physics and Latvian State University mainly for spectroscopic studies, holography and material processing. In 1986, the first picosecond YAG:Nd3+ laser with active mode locking was built in the Institute of Solid State Physics, Latvian State U ...
StarLux 500 Technical Specifications
... “It’s wonderful to be able to treat some cosmetic indications that traditionally I’ve had to treat with ablative technology. The Lux1540 is the best alternative for rejuvenation of the neck and chest and for treatment of acne scars.” ...
... “It’s wonderful to be able to treat some cosmetic indications that traditionally I’ve had to treat with ablative technology. The Lux1540 is the best alternative for rejuvenation of the neck and chest and for treatment of acne scars.” ...
Laser radiation versus “ordinary light”
... High intensity of radiation even for very low power rating of laser. (A 50 Watt laser can be very dangerous while a 50 Watt light bulb is rather harmless). When high intensities are absorbed in biological or other materials they can cause damage (eye damage, blindness, burns of other body parts, fi ...
... High intensity of radiation even for very low power rating of laser. (A 50 Watt laser can be very dangerous while a 50 Watt light bulb is rather harmless). When high intensities are absorbed in biological or other materials they can cause damage (eye damage, blindness, burns of other body parts, fi ...
SUPPLEMENTAL MATERIA_Revised2
... threshold of about 150 µJ/cm2. Below the threshold, the spectrum of spontaneous emission from CQDs was observed as expected, and above threshold, a multi-mode laser spectrum was emerged from the background spontaneous emission. (The laser lines emerge on strong spontaneous emission background as a r ...
... threshold of about 150 µJ/cm2. Below the threshold, the spectrum of spontaneous emission from CQDs was observed as expected, and above threshold, a multi-mode laser spectrum was emerged from the background spontaneous emission. (The laser lines emerge on strong spontaneous emission background as a r ...
Laser - bYTEBoss
... Gordon Gould was the first person to use the word "laser". There is good reason to believe that Gordon Gould made the first light laser. Gordon Gould was first inspired to build his optical laser starting in 1958. He failed to file for a patent his invention until 1959. As a result, Gordon Gould's p ...
... Gordon Gould was the first person to use the word "laser". There is good reason to believe that Gordon Gould made the first light laser. Gordon Gould was first inspired to build his optical laser starting in 1958. He failed to file for a patent his invention until 1959. As a result, Gordon Gould's p ...
lecture 36 - waves in 3 dimensions, optical devices
... What wavelength do you want the wave to have? What do you want the wave’s amplitude to be? What frequency (or velocity) do you want the wave to have? What do you want the overall phase of the wave to be? ...
... What wavelength do you want the wave to have? What do you want the wave’s amplitude to be? What frequency (or velocity) do you want the wave to have? What do you want the overall phase of the wave to be? ...
Fiber Optic Communications
... – An external photon hits an excited electron forcing another photon to be emitted at the same wavelength. That created photon excites another, etc. ...
... – An external photon hits an excited electron forcing another photon to be emitted at the same wavelength. That created photon excites another, etc. ...
CS - Classes
... Prerequisites: ECE 391 or PH 481 or equivalent – some basic optics and plane wave theory is useful but PH 211-213 could suffice. Courses that require this as a prerequisite: ECE 592 Structure: Three 50-minute lectures plus one 3-hour lab per week Instructors: T. Plant (primary), A. Weisshaar (second ...
... Prerequisites: ECE 391 or PH 481 or equivalent – some basic optics and plane wave theory is useful but PH 211-213 could suffice. Courses that require this as a prerequisite: ECE 592 Structure: Three 50-minute lectures plus one 3-hour lab per week Instructors: T. Plant (primary), A. Weisshaar (second ...
Lasers
... L is the cavity length c is speed of light these modes may each have their own amplitude En thus the optical field in the cavity can be written: ...
... L is the cavity length c is speed of light these modes may each have their own amplitude En thus the optical field in the cavity can be written: ...
Laser pumping
Laser pumping is the act of energy transfer from an external source into the gain medium of a laser. The energy is absorbed in the medium, producing excited states in its atoms. When the number of particles in one excited state exceeds the number of particles in the ground state or a less-excited state, population inversion is achieved. In this condition, the mechanism of stimulated emission can take place and the medium can act as a laser or an optical amplifier. The pump power must be higher than the lasing threshold of the laser.The pump energy is usually provided in the form of light or electric current, but more exotic sources have been used, such as chemical or nuclear reactions.