Analysis of Strained Al0.15In0.22Ga0.63As/GaAs Graded Index
... Al0.15In0.22Ga0.63As/GaAs strained single quantum well based Graded Index (GRIN) - separate confinement lasing nano-heterostructure. Major emphasis has been laid on the optical and modal gain. Both these gain have been simulated with respect to lasing wavelength, photon energy and current density. I ...
... Al0.15In0.22Ga0.63As/GaAs strained single quantum well based Graded Index (GRIN) - separate confinement lasing nano-heterostructure. Major emphasis has been laid on the optical and modal gain. Both these gain have been simulated with respect to lasing wavelength, photon energy and current density. I ...
Template
... The first step of the numerical scheme is the solution of the ten-band k·p Hamiltonian which includes the dilute nitrogen levels responsible for the extra nonparabolicity that gives rise to strong differences in effective subband masses. The Green’s functions and self-energies are expanded using ei ...
... The first step of the numerical scheme is the solution of the ten-band k·p Hamiltonian which includes the dilute nitrogen levels responsible for the extra nonparabolicity that gives rise to strong differences in effective subband masses. The Green’s functions and self-energies are expanded using ei ...
Theoretical study on Brillouin fiber laser sensor Omer Kotlicki, Jacob Scheuer,
... the phase element is needed. Although such control is difficult in integrated optics, tunable fiber couplers are available and fiber Bragg grating mirrors can be tension-controlled to produce the necessary reflection coefficient. In addition, fiber optics possesses extremely low loss which is import ...
... the phase element is needed. Although such control is difficult in integrated optics, tunable fiber couplers are available and fiber Bragg grating mirrors can be tension-controlled to produce the necessary reflection coefficient. In addition, fiber optics possesses extremely low loss which is import ...
Excitation of Rydberg states in rubidium with near infrared diode lasers
... formation of an ultracold plasma [13–16]. The extremely low collision energies between ultracold atoms also makes possible the formation of exotic ultralong-range Rydberg molecules. In one example of these exotic molecules, a pair of Rydberg atoms is bound together forming a macrodimer with a size g ...
... formation of an ultracold plasma [13–16]. The extremely low collision energies between ultracold atoms also makes possible the formation of exotic ultralong-range Rydberg molecules. In one example of these exotic molecules, a pair of Rydberg atoms is bound together forming a macrodimer with a size g ...
Manipulating atoms with photons (Nobel lecture of C. Cohen
... same frequency and they are slightly detuned to the red of the atomic frequency ( v L , v A ). For an atom at rest, the two radiation pressure forces exactly balance each other and the net force is equal to zero. For a moving atom, the apparent frequencies of the two laser waves are Doppler shifted. ...
... same frequency and they are slightly detuned to the red of the atomic frequency ( v L , v A ). For an atom at rest, the two radiation pressure forces exactly balance each other and the net force is equal to zero. For a moving atom, the apparent frequencies of the two laser waves are Doppler shifted. ...
Simple 3-D characterization of ultrashort laser pulses
... phase of the electric field can be retrieved. The precision provided by these techniques is difficult to achieve with other methods, but these correlation measurements are often averaged across the section of the laser beam. Thus, to increase the reliability and the precision of experiments using ul ...
... phase of the electric field can be retrieved. The precision provided by these techniques is difficult to achieve with other methods, but these correlation measurements are often averaged across the section of the laser beam. Thus, to increase the reliability and the precision of experiments using ul ...
Optical Characterization of Quantum Dots
... a thin InAs layer on top of GaAs forms a strained layer, the wetting layer. This strain increases further by increasing the wetting layer thickness. At a critical thickness of the InAs (1.7 monolayer) the accumulated strain is relieved by the epitaxial islanding transition [14]. This transition lead ...
... a thin InAs layer on top of GaAs forms a strained layer, the wetting layer. This strain increases further by increasing the wetting layer thickness. At a critical thickness of the InAs (1.7 monolayer) the accumulated strain is relieved by the epitaxial islanding transition [14]. This transition lead ...
Quantum state-resolved probing of strong-field
... level to the 5p valence shell. These measurements allow the determination of the complete |j, mi quantum state distribution, which is compared to theory. The schematic of the experimental setup is illustrated in Fig. 1. Briefly, the amplified output from a commercial Ti:sapphire laser system (2.4 W, ...
... level to the 5p valence shell. These measurements allow the determination of the complete |j, mi quantum state distribution, which is compared to theory. The schematic of the experimental setup is illustrated in Fig. 1. Briefly, the amplified output from a commercial Ti:sapphire laser system (2.4 W, ...
The Impact of Energy Band Diagram and Inhomogeneous
... the large number of discrete states keeps the state filling reduction in the valence band considerably lower than one. Large differential gain in room temperature conventional SAQD lasers may be predicted based on the conduction band filling reduction whose peak values may exceed considerably the va ...
... the large number of discrete states keeps the state filling reduction in the valence band considerably lower than one. Large differential gain in room temperature conventional SAQD lasers may be predicted based on the conduction band filling reduction whose peak values may exceed considerably the va ...
Concentration-dependent absorption and emission behaviour of
... by using the dye rhodamine 101 in ethanol as reference dye (fluorescencequantum yield <^R«0.98 [3033 ] ) . U p to a concentration of 0.1 mol/dm dichroitic polarizers in the excitation path (vertical orientation) and detection path (orientation under an angle of 54.74° to the vertical axis) were used ...
... by using the dye rhodamine 101 in ethanol as reference dye (fluorescencequantum yield <^R«0.98 [3033 ] ) . U p to a concentration of 0.1 mol/dm dichroitic polarizers in the excitation path (vertical orientation) and detection path (orientation under an angle of 54.74° to the vertical axis) were used ...
Particles in a gas may be viewed as wavepackets with an extent of
... Let us consider an atom moving in a direction opposing the laser beam (for the moment, we will consider only the velocity component in the same axis as the beam). If it absorbs a photon, its velocity is reduced, since the direction of Δv is directly opposed to that of the atom’s velocity v. As the a ...
... Let us consider an atom moving in a direction opposing the laser beam (for the moment, we will consider only the velocity component in the same axis as the beam). If it absorbs a photon, its velocity is reduced, since the direction of Δv is directly opposed to that of the atom’s velocity v. As the a ...
Conservation laws and laser cooling of atoms
... enter the description: the parameter B1 = v1 /c, where v1 is the norm of the atom’s velocity vector ~v1 before the absorption/emission of a photon. The use of dimensionless parameters simplify the formulas and allows an easy comparison of the orders of magnitude; however, when needed, the basic phys ...
... enter the description: the parameter B1 = v1 /c, where v1 is the norm of the atom’s velocity vector ~v1 before the absorption/emission of a photon. The use of dimensionless parameters simplify the formulas and allows an easy comparison of the orders of magnitude; however, when needed, the basic phys ...
Non-reciprocal ultrafast laser writing
... recombine with nearby ions in just a few nanoseconds or even faster. However, at the pulse repetition rate of 250 kHz, the time interval between laser pulses is at least 1,000 times longer. What is there that ‘remembers’ what direction the laser beam is being translated in 4 ms later, when the next ...
... recombine with nearby ions in just a few nanoseconds or even faster. However, at the pulse repetition rate of 250 kHz, the time interval between laser pulses is at least 1,000 times longer. What is there that ‘remembers’ what direction the laser beam is being translated in 4 ms later, when the next ...
Sample Chapter
... region is the light guiding region known as the core. It is surrounded by a coaxial middle region known as the cladding. The outermost region is called the sheath. The refractive index of cladding is always lower than that of the core. The purpose of cladding is to make the light to be confined to t ...
... region is the light guiding region known as the core. It is surrounded by a coaxial middle region known as the cladding. The outermost region is called the sheath. The refractive index of cladding is always lower than that of the core. The purpose of cladding is to make the light to be confined to t ...
Quantum treatment of two-stage sub
... Laser cooling of neutral atoms in a magneto-optical trap is one of the main cooling methods. At first time the laser field composed of six beams with orthogonal circular polarizations (σ + σ − configuration) was suggested in [49] as effective way for simultaneous cooling and trapping of atoms. Narro ...
... Laser cooling of neutral atoms in a magneto-optical trap is one of the main cooling methods. At first time the laser field composed of six beams with orthogonal circular polarizations (σ + σ − configuration) was suggested in [49] as effective way for simultaneous cooling and trapping of atoms. Narro ...
Optical properties of small-bore hollow glass waveguides
... When the waveguides are used in medical or industrial applications, it is often desirable to maintain the spatial purity of the input laser beam because it is necessary to cut or ablate with as small a spot size as possible. To evaluate the mode purity of the output beam, we measured the output beam ...
... When the waveguides are used in medical or industrial applications, it is often desirable to maintain the spatial purity of the input laser beam because it is necessary to cut or ablate with as small a spot size as possible. To evaluate the mode purity of the output beam, we measured the output beam ...
Photoexfoliation of Graphene from Graphite: An Ab Initio Study Yoshiyuki Miyamoto,
... FIG. 2 (color online). Schematic layer stacking (a) and structural snapshots (b) of the surface of AB-stacked graphite during exposure to a FWHM ¼ 45 fs laser pulse. (c) Time evolution of the interlayer distances. (d) Time-dependence of the optical electric field E characterizing the laser pulse. ...
... FIG. 2 (color online). Schematic layer stacking (a) and structural snapshots (b) of the surface of AB-stacked graphite during exposure to a FWHM ¼ 45 fs laser pulse. (c) Time evolution of the interlayer distances. (d) Time-dependence of the optical electric field E characterizing the laser pulse. ...
Non-thermal laser-induced desorption of metal atoms with bimodal
... release of heat into a lower-lying level before desorption takes place. Depending on the photon energy used to stimulate desorption, this process populates a state that is located more than 1 eV above the ground level. The experimental results allow us to suggest a desorption mechanism along the lin ...
... release of heat into a lower-lying level before desorption takes place. Depending on the photon energy used to stimulate desorption, this process populates a state that is located more than 1 eV above the ground level. The experimental results allow us to suggest a desorption mechanism along the lin ...
Cavity dark states for quantum computing M.S. Shahriar , J.A. Bowers
... excited state lifetime, the potential bene®t of using the dark state is mitigated substantially. Furthermore, there are situations where the cavity decay rate is orders of magnitude bigger than the line width of the atomic system, so that the bene®t of using the dark state is minimal. For example, w ...
... excited state lifetime, the potential bene®t of using the dark state is mitigated substantially. Furthermore, there are situations where the cavity decay rate is orders of magnitude bigger than the line width of the atomic system, so that the bene®t of using the dark state is minimal. For example, w ...
Light fan driven by relativistic laser pulse
... can be transported to a small volume in very short time. The twisted light with strongest torque by far can be found in twisted laser driven HHG experiments. In the experiments of Zurch et al. [21], a 800 nm laser is reflected from the spatial light modulator to obtain a twisted light with peaking i ...
... can be transported to a small volume in very short time. The twisted light with strongest torque by far can be found in twisted laser driven HHG experiments. In the experiments of Zurch et al. [21], a 800 nm laser is reflected from the spatial light modulator to obtain a twisted light with peaking i ...
[pdf]
... ZnSe-GaAs(001) heterojunction. This contribution provides information about the effects of defects on free carriers and provides an example of how modulation techniques can be combined with nonlinear optical spectroscopies to provide low background information about interfaces. The quantities to whi ...
... ZnSe-GaAs(001) heterojunction. This contribution provides information about the effects of defects on free carriers and provides an example of how modulation techniques can be combined with nonlinear optical spectroscopies to provide low background information about interfaces. The quantities to whi ...
Ultrafast electronic dynamics in polyatomic molecules studied using
... light source, a free electron laser is a large-scale facility to generate ultrashort and ultraintense pulses from the VUV to hard x-ray region [9–12]. There are already a number of free electron lasers around the world, such as FLASH (free electron LASer in Hamburg), SCSS (SPring-8 Compact SASE sour ...
... light source, a free electron laser is a large-scale facility to generate ultrashort and ultraintense pulses from the VUV to hard x-ray region [9–12]. There are already a number of free electron lasers around the world, such as FLASH (free electron LASer in Hamburg), SCSS (SPring-8 Compact SASE sour ...
Semiconductor Lasers Using Diffused Quantum
... where disordering occurs will be reduced significantly by the increase of background temperature. Another advantage of using ceramic is that its low thermal conductivity also helps in reducing the required power density of laser beam. Therefore, the irradiation of laser light of 5 W/mm power density ...
... where disordering occurs will be reduced significantly by the increase of background temperature. Another advantage of using ceramic is that its low thermal conductivity also helps in reducing the required power density of laser beam. Therefore, the irradiation of laser light of 5 W/mm power density ...
Scattered Light Predictions for Aluminum Painted Reflectors in
... Figure 10 [5]. An average correlation coefficient of 0.981 was achieved. ...
... Figure 10 [5]. An average correlation coefficient of 0.981 was achieved. ...
Introduction to Flow Cytometry: A Learning Guide
... fluorescent compound to be raised to a higher energy level. The excited electron quickly decays to its ground state, emitting the excess energy as a photon of light. This transition of energy is called fluorescence. The range over which a fluorescent compound can be excited is termed its absorption ...
... fluorescent compound to be raised to a higher energy level. The excited electron quickly decays to its ground state, emitting the excess energy as a photon of light. This transition of energy is called fluorescence. The range over which a fluorescent compound can be excited is termed its absorption ...
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.