File - GENERAL DEPARTMENT
... Fig.-1 shows that the atom is in its excited state and no external radiation is present. It comes to this state after absorbing a photon of energy hf or by some other inelastic collision. The atom has now become an excited atom. A short time later, the atom will move itself to its ground state, emit ...
... Fig.-1 shows that the atom is in its excited state and no external radiation is present. It comes to this state after absorbing a photon of energy hf or by some other inelastic collision. The atom has now become an excited atom. A short time later, the atom will move itself to its ground state, emit ...
Optical Sources
... – Critical angle is between semiconductor and plastic – Angle between plastic and air is near normal – Normal reflection is reduced – Dome makes LED more directional ...
... – Critical angle is between semiconductor and plastic – Angle between plastic and air is near normal – Normal reflection is reduced – Dome makes LED more directional ...
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). ...
JMacePaper.doc
... it is the metal that is actually excited to produce laser light. Common types of these lasers are Ruby (Cr3+ in Al2O3), Neodymium in Yttrium Aluminum Garnet (Nd:YAG), and Erbium in Glass. These usually have a Xenon lamp or a light emitting diode array as a pumping source. Their uses typically includ ...
... it is the metal that is actually excited to produce laser light. Common types of these lasers are Ruby (Cr3+ in Al2O3), Neodymium in Yttrium Aluminum Garnet (Nd:YAG), and Erbium in Glass. These usually have a Xenon lamp or a light emitting diode array as a pumping source. Their uses typically includ ...
engineering physics
... Quantum Mechanics : Matter waves - Schroedinger’s time independent wave equation - Physical significance of the wave function - Particle in one dimensional potential well – tunneling phenomenon. Free electron theory of metals : Introduction – Classical free electron theory – Electrical conductivity ...
... Quantum Mechanics : Matter waves - Schroedinger’s time independent wave equation - Physical significance of the wave function - Particle in one dimensional potential well – tunneling phenomenon. Free electron theory of metals : Introduction – Classical free electron theory – Electrical conductivity ...
Microsoft Word Format - University of Toronto Physics
... A laser is an optical oscillator and thus consists of an amplifier with positive feedback. The amplification in a He-Ne laser arises in the glow discharge while feedback of the optical radiation is provided by two highly reflecting, well aligned mirrors. The conditions necessary for amplification ar ...
... A laser is an optical oscillator and thus consists of an amplifier with positive feedback. The amplification in a He-Ne laser arises in the glow discharge while feedback of the optical radiation is provided by two highly reflecting, well aligned mirrors. The conditions necessary for amplification ar ...
HeNe The Helium-Neon Laser - University of Toronto Physics
... (2p) 3p levels of Ne. The inversion arises principally from inelastic collisions between Ne atoms in their ground state and He atoms in their 21So metastable level. The details of the excitation transfer mechanism as well as the various atomic level notations are discussed in Appendices I and II. St ...
... (2p) 3p levels of Ne. The inversion arises principally from inelastic collisions between Ne atoms in their ground state and He atoms in their 21So metastable level. The details of the excitation transfer mechanism as well as the various atomic level notations are discussed in Appendices I and II. St ...
4.6 Optical Fibres
... Light has to be launched into a fibre. Communication fibre uses lasers but for local networks light-emitting diodes may be used. Light travels through the fibre by total internal reflection bouncing off the interface between the core and cladding. The cladding must have a lower refractive index comp ...
... Light has to be launched into a fibre. Communication fibre uses lasers but for local networks light-emitting diodes may be used. Light travels through the fibre by total internal reflection bouncing off the interface between the core and cladding. The cladding must have a lower refractive index comp ...
Laser Safety Fundamentals
... These atoms spontaneously decay to a relatively long-lived, lower energy, metastable state. A population inversion is achieved when the majority of atoms have reached this metastable state. Lasing action occurs when an electron spontaneously returns to its ground state and produces a photon. ...
... These atoms spontaneously decay to a relatively long-lived, lower energy, metastable state. A population inversion is achieved when the majority of atoms have reached this metastable state. Lasing action occurs when an electron spontaneously returns to its ground state and produces a photon. ...
4/10/2006 Chapter 37 Lasers, a Model Atom and Zero Point Energy
... onto a solid theoretical foundation with the development of the Schrodinger Wave Equation. This equation can be used to calculate the energy values for electrons in hydrogen (and other atoms). This field of physics dealing with “Wave Mechanics” came to be called Quantum Mechanics. The next few chapt ...
... onto a solid theoretical foundation with the development of the Schrodinger Wave Equation. This equation can be used to calculate the energy values for electrons in hydrogen (and other atoms). This field of physics dealing with “Wave Mechanics” came to be called Quantum Mechanics. The next few chapt ...
I. Introduction - Politecnico di Torino
... Semiconductor mode locked laser diodes are very compact and efficient sources for generation of short optical pulses at high repetition rate. They are mainly used in optical telecommunications [1] (high bit rate transmissions, all optical clock recovery, millimeter wave generation). They can also be ...
... Semiconductor mode locked laser diodes are very compact and efficient sources for generation of short optical pulses at high repetition rate. They are mainly used in optical telecommunications [1] (high bit rate transmissions, all optical clock recovery, millimeter wave generation). They can also be ...
The excitation mechanism excitation mechanism
... with the gas molecules and transfer energy to them. Thus, the gas molecules are raised to excited state. Higher voltage is required to start the electrical discharge in the tube than to keep the discharge. Thus, a preliminary high voltage pulse is applied for initial discharge, and then the voltage ...
... with the gas molecules and transfer energy to them. Thus, the gas molecules are raised to excited state. Higher voltage is required to start the electrical discharge in the tube than to keep the discharge. Thus, a preliminary high voltage pulse is applied for initial discharge, and then the voltage ...
How laser works
... transitory, lasting only about one-millionth of a second. A small pulse of laser light "tuned" to the excited electrons' energy is directed through the glass slabs. This laser pulse stimulates the electrons to drop to their lower energy states, or "ground" states, and emit a laser photon of exactly ...
... transitory, lasting only about one-millionth of a second. A small pulse of laser light "tuned" to the excited electrons' energy is directed through the glass slabs. This laser pulse stimulates the electrons to drop to their lower energy states, or "ground" states, and emit a laser photon of exactly ...
1. Which of the following statement are true about "LED life" term?
... Emitted light directly supply from a electric current In fotovoltaic mode, an external reverse bias is applied to the photodiode and in fotoconductive mode is un-biased Has a fastest switching speed when operates in photoconductive mode 9. An optical amplifiers is a device that: Amplifies the optica ...
... Emitted light directly supply from a electric current In fotovoltaic mode, an external reverse bias is applied to the photodiode and in fotoconductive mode is un-biased Has a fastest switching speed when operates in photoconductive mode 9. An optical amplifiers is a device that: Amplifies the optica ...
Young`s Double Slits
... LABORATORY DEMONSTRATOR. Operational Hazard – Semiconductor laser diodes The two laser sources you will be using emit green and red visible light. Both are categorised as class 2 sources and thus defined to be eye safe (i.e. the human blink reflex will be sufficient to prevent damaging exposure), ha ...
... LABORATORY DEMONSTRATOR. Operational Hazard – Semiconductor laser diodes The two laser sources you will be using emit green and red visible light. Both are categorised as class 2 sources and thus defined to be eye safe (i.e. the human blink reflex will be sufficient to prevent damaging exposure), ha ...
Chapter 4 Optical Source
... • Heterojunction is the advanced junction design to reduce diffraction loss in the optical cavity. • This is accomplished by modification of the laser material to control the index of refraction of the cavity and the width of the junction. • The Heterojunction region is actually lightly doped with p ...
... • Heterojunction is the advanced junction design to reduce diffraction loss in the optical cavity. • This is accomplished by modification of the laser material to control the index of refraction of the cavity and the width of the junction. • The Heterojunction region is actually lightly doped with p ...
7_laser - WordPress.com
... The atoms by induced absorption reach excited state E2 from E0. They stay there only for 10-8 seconds. After this time they fall to met-stable state where they stay for quite a longer time (10-3 seconds). Within this longer time more number of atoms get collected in the meta-stable state which is la ...
... The atoms by induced absorption reach excited state E2 from E0. They stay there only for 10-8 seconds. After this time they fall to met-stable state where they stay for quite a longer time (10-3 seconds). Within this longer time more number of atoms get collected in the meta-stable state which is la ...
Microwave frequency generation using a dual
... The authors wish to acknowledge the Redfern Optical Component for supplying with gratings REFERENCES ...
... The authors wish to acknowledge the Redfern Optical Component for supplying with gratings REFERENCES ...
optical cavity
... and plotting g1 against g2 as shown. Areas bounded by the line g1 g2 = 1 and the axes are stable. Cavities at points exactly on the line are marginally stable; small variations in cavity length can cause the resonator to become unstable, and so lasers using these cavities are in practice often opera ...
... and plotting g1 against g2 as shown. Areas bounded by the line g1 g2 = 1 and the axes are stable. Cavities at points exactly on the line are marginally stable; small variations in cavity length can cause the resonator to become unstable, and so lasers using these cavities are in practice often opera ...
Chapter 4 Optical Sources
... The photon produced by stimulated emission is generally of an identical energy to the one which caused it and hence the light associated with them is the same frequency – Monocromatic The light associated with the stimulating and stimulated photon is in phase and has a same polarization – Coherent F ...
... The photon produced by stimulated emission is generally of an identical energy to the one which caused it and hence the light associated with them is the same frequency – Monocromatic The light associated with the stimulating and stimulated photon is in phase and has a same polarization – Coherent F ...
Slide 1
... specific laser is determined based on the wavelength and exposure duration. Nominal Hazard Zone(NHZ) is the space within which level of the direct, reflected, or scattered radiation during normal operation exceeds the applicable MPE. Exposure levels beyond the boundary of the NHZ are below the appro ...
... specific laser is determined based on the wavelength and exposure duration. Nominal Hazard Zone(NHZ) is the space within which level of the direct, reflected, or scattered radiation during normal operation exceeds the applicable MPE. Exposure levels beyond the boundary of the NHZ are below the appro ...
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term ""laser"" originated as an acronym for ""light amplification by stimulated emission of radiation"". The first laser was built in 1960 by Theodore H. Maiman at Hughes Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond.Among their many applications, lasers are used in optical disk drives, laser printers, and barcode scanners; fiber-optic and free-space optical communication; laser surgery and skin treatments; cutting and welding materials; military and law enforcement devices for marking targets and measuring range and speed; and laser lighting displays in entertainment.