Class 23
... Population inversion means: More atoms are in the excited state than in the ground state. As soon as we have the same number of atoms in the excited state as in the ground state, the probability of creating an excited atom is same (or smaller, when considering spontaneous emission) as the probabilit ...
... Population inversion means: More atoms are in the excited state than in the ground state. As soon as we have the same number of atoms in the excited state as in the ground state, the probability of creating an excited atom is same (or smaller, when considering spontaneous emission) as the probabilit ...
The Fabry-Perot Cavity
... dPe/dI is called the slope efficiency (units of W/A) ηd is called the differential quantum efficiency (units of %) ...
... dPe/dI is called the slope efficiency (units of W/A) ηd is called the differential quantum efficiency (units of %) ...
Exercice N°1 : Laser à 4 niveaux
... population densities are independent of the position in the medium. The pumping is longitudinal such that the pump beam and the cavity beam have exactly the same shape and the same size (the overlap between the two beams is perfect). ...
... population densities are independent of the position in the medium. The pumping is longitudinal such that the pump beam and the cavity beam have exactly the same shape and the same size (the overlap between the two beams is perfect). ...
Diode Pumped Solid State
... able to dominate over absorbtion and spontaneous emission, and secondly there must be an optical cavity. Fortunately both are relatively simple to achieve. The population inversion required for stimulated emission to dominate is realised by increasing the current through the diode. This increases th ...
... able to dominate over absorbtion and spontaneous emission, and secondly there must be an optical cavity. Fortunately both are relatively simple to achieve. The population inversion required for stimulated emission to dominate is realised by increasing the current through the diode. This increases th ...
7.1.3 Optimizing Light Confinement and Gain in Laser Diodes
... For currents below some threshold current Ith, the device will be a simple LED emitting light with a rather wide frequency distribution. As soon as enough carriers are injected to cause sufficient inversion, some modes of the resonator with the "right" wavelengths will become amplified and appear as ...
... For currents below some threshold current Ith, the device will be a simple LED emitting light with a rather wide frequency distribution. As soon as enough carriers are injected to cause sufficient inversion, some modes of the resonator with the "right" wavelengths will become amplified and appear as ...
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? ...
AO for high peak power lasers
... Adaptive optics for high-power lasers Things that make AO for high-power lasers easier 1. Plenty of light (!) 2. Controlled environment (stable temperature, indoors, enclosed beams) 3. No need for an extended field of view (point focus only) 4. Only slow response needed (at present . . .) Things th ...
... Adaptive optics for high-power lasers Things that make AO for high-power lasers easier 1. Plenty of light (!) 2. Controlled environment (stable temperature, indoors, enclosed beams) 3. No need for an extended field of view (point focus only) 4. Only slow response needed (at present . . .) Things th ...
Laser Molecular Spectroscopy CHE466 Fall 2007
... The other process necessary for a laser is the effect of amplifying the stimulated emission process. For such a process the lasing medium must be enclosed in an accurately aligned optical cavity, in which the emitted photons are confined to bounce back to the sample to stimulate further emission (op ...
... The other process necessary for a laser is the effect of amplifying the stimulated emission process. For such a process the lasing medium must be enclosed in an accurately aligned optical cavity, in which the emitted photons are confined to bounce back to the sample to stimulate further emission (op ...
LASERS How do they work?
... within the cavity and wander out of it. The laser cavity also improves the spectral purity of the laser beam. Usually, the amplifying medium will amplify light within a narrow range of wavelengths. However, within this narrow range, only light of particular wavelengths can undergo repeated reflectio ...
... within the cavity and wander out of it. The laser cavity also improves the spectral purity of the laser beam. Usually, the amplifying medium will amplify light within a narrow range of wavelengths. However, within this narrow range, only light of particular wavelengths can undergo repeated reflectio ...
Lab 11: Atomic Spectra
... lower frequencies. For example, an atom can absorb a UV photon and jump to a higher energy state. Rather then jumping directly back to the initial energy state (and emitting the same energy UV photon), the atom can make several smaller jumps and emit lower energy photons (such as visible light). Thi ...
... lower frequencies. For example, an atom can absorb a UV photon and jump to a higher energy state. Rather then jumping directly back to the initial energy state (and emitting the same energy UV photon), the atom can make several smaller jumps and emit lower energy photons (such as visible light). Thi ...
The Interaction of Radiation and Matter: Semiclassical
... emitted from excited chromium ions cause stimulated emission from other excited ions" "The ruby laser is often referred to as an example of a three-level system. More than three energy levels are actually involved but they can be put into three categories. These are; the lower level form which pumpi ...
... emitted from excited chromium ions cause stimulated emission from other excited ions" "The ruby laser is often referred to as an example of a three-level system. More than three energy levels are actually involved but they can be put into three categories. These are; the lower level form which pumpi ...
Laser Physics I
... a photon of the same frequency and 75 % Mirror direction of the incident photon. Lasers have 3 parts: 1. Gain medium – a place for stimulated emmision to occur (crystal, gas, etc.) 2. Positive feedback – means for oscillation (mirrors, diffraction grating, etc.) 3. Source of energy – an incoming ene ...
... a photon of the same frequency and 75 % Mirror direction of the incident photon. Lasers have 3 parts: 1. Gain medium – a place for stimulated emmision to occur (crystal, gas, etc.) 2. Positive feedback – means for oscillation (mirrors, diffraction grating, etc.) 3. Source of energy – an incoming ene ...
Experimental proposal for electromagnetically
... gives rise to its transparency. The center one is composed of numerous and very small interconnected single crystals that the boundaries between these small crystals scatter a portion of the light reflected from the printed page, which makes this material optically translucent. And finally, the spec ...
... gives rise to its transparency. The center one is composed of numerous and very small interconnected single crystals that the boundaries between these small crystals scatter a portion of the light reflected from the printed page, which makes this material optically translucent. And finally, the spec ...
Registration Penning electrons from atomic impurities in nonlocal
... current-voltage characteristics in which the observed spectrum of Penning electron energy (energy peaks) in a mixture of helium and argon in the pressure range of the main gas (helium) 18-100 Torr, and an impurity gas (argon) 0.1-1.7 %, as well as a mixture of helium and krypton at respective pressu ...
... current-voltage characteristics in which the observed spectrum of Penning electron energy (energy peaks) in a mixture of helium and argon in the pressure range of the main gas (helium) 18-100 Torr, and an impurity gas (argon) 0.1-1.7 %, as well as a mixture of helium and krypton at respective pressu ...
Michael_Chau_Laeer_Telecomunication_Report
... with the laser emitter decreased the voltage from 3 V to 2.46 V across the laser. Consequently, it appeared necessary to increase the voltage appreciably to compensate for the voltage reduction. Initially, we intended to demonstrate both video and audio using the modulated laser but the former becam ...
... with the laser emitter decreased the voltage from 3 V to 2.46 V across the laser. Consequently, it appeared necessary to increase the voltage appreciably to compensate for the voltage reduction. Initially, we intended to demonstrate both video and audio using the modulated laser but the former becam ...
doc
... The free-electron laser (FEL) is an ideal instrument for charting the interactions of light and matter in many of the still unexplored regions of the electromagnetic spectrum. As a laser 1, it produces light in a single wavelength. Ordinary white light contains particles of light, or photons, with a ...
... The free-electron laser (FEL) is an ideal instrument for charting the interactions of light and matter in many of the still unexplored regions of the electromagnetic spectrum. As a laser 1, it produces light in a single wavelength. Ordinary white light contains particles of light, or photons, with a ...
Compiled questions (docx 32 kB)
... scanning microscope the dependence is linear. Nonlinear microscopy methods might have linear or quadratic dependence. Which dependence on concentration you would expect in following nonlinear methods: (a) SHG, (b) SFM, (c) TPFE, (d) CARS, (e) heterodyne CARS, (f) SRS. 2. In all microscopy methods wh ...
... scanning microscope the dependence is linear. Nonlinear microscopy methods might have linear or quadratic dependence. Which dependence on concentration you would expect in following nonlinear methods: (a) SHG, (b) SFM, (c) TPFE, (d) CARS, (e) heterodyne CARS, (f) SRS. 2. In all microscopy methods wh ...
LASER IN Medicine
... Population Inversion. This is a mechanism by which we can add more atoms to the metastable level and hold them there long enough for them to store energy, thereby allowing the production of great numbers of stimulated photons. To do this, we pump atoms into the metastable level at a rate that exceed ...
... Population Inversion. This is a mechanism by which we can add more atoms to the metastable level and hold them there long enough for them to store energy, thereby allowing the production of great numbers of stimulated photons. To do this, we pump atoms into the metastable level at a rate that exceed ...
Allee_Linda - Arizona Space Grant Consortium
... • Requires accurate alignment within the laser • Not very robust ...
... • Requires accurate alignment within the laser • Not very robust ...
L 35 Modern Physics [1]
... and the Bohr Atom • Niels Bohr, a Danish physicist, used the quantum concept to explain the nature of the atom. • Recall that the orbiting electrons, according to classical ideas, should very quickly radiate away all of its energy • If this were so, then we would observe that atoms emit light over a ...
... and the Bohr Atom • Niels Bohr, a Danish physicist, used the quantum concept to explain the nature of the atom. • Recall that the orbiting electrons, according to classical ideas, should very quickly radiate away all of its energy • If this were so, then we would observe that atoms emit light over a ...
Excited State Processes and Application to Lasers The technology
... The laser phenomenon involves a stimulated emission of light that results in gain. One input photon can stimulate emission of a second photon, which initiates a chain reaction. However, in order for such a chain reaction to take place the system must be poised so that there is a great deal of excess ...
... The laser phenomenon involves a stimulated emission of light that results in gain. One input photon can stimulate emission of a second photon, which initiates a chain reaction. However, in order for such a chain reaction to take place the system must be poised so that there is a great deal of excess ...
I Laser A laser is a device that emits light (electromagnetic radiation
... very tiny spots, achieving a very high irradiance, or they can be launched into beams of very low divergence in order to concentrate their power at a large distance. Temporal (or longitudinal) coherence implies a polarized wave at a single frequency whose phase is correlated over a relatively large ...
... very tiny spots, achieving a very high irradiance, or they can be launched into beams of very low divergence in order to concentrate their power at a large distance. Temporal (or longitudinal) coherence implies a polarized wave at a single frequency whose phase is correlated over a relatively large ...
Excited States, Lasers and Non-Linear Optics
... Second harmonic generation was first demonstrated by Franken, Hill, Peters, and Weinreich at the University of Michigan, Ann Arbor, in 1961. The demonstration was made possible by the invention of the laser, which created the required high intensity monochromatic light. They focused a ruby laser wit ...
... Second harmonic generation was first demonstrated by Franken, Hill, Peters, and Weinreich at the University of Michigan, Ann Arbor, in 1961. The demonstration was made possible by the invention of the laser, which created the required high intensity monochromatic light. They focused a ruby laser wit ...
Birla Institute of Technology and Science, Pilani and Elite School of Optometry
... 1.2. Light as transverse oscillations of electromagnetic fields; sine waves. 1.3. Concepts of amplitude, phase and intensity. 1.4. Concepts of wavefronts; Huygens principle; Sinusoidal waves. 1.5 Electromagnetic spectrum; visible spectrum; UV; UV-A, UV-B, UV-C; IR - far and near IR radiations; X-ray ...
... 1.2. Light as transverse oscillations of electromagnetic fields; sine waves. 1.3. Concepts of amplitude, phase and intensity. 1.4. Concepts of wavefronts; Huygens principle; Sinusoidal waves. 1.5 Electromagnetic spectrum; visible spectrum; UV; UV-A, UV-B, UV-C; IR - far and near IR radiations; X-ray ...
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.