101 research outputs found
Model for self-consistent analysis of arbitrary MQW structures
Self-consistent computations of the potential profile in complex
semiconductor heterostructures can be successfully applied for comprehensive
simulation of the gain and the absorption spectra, for the analysis of the
capture, escape, tunneling, recombination, and relaxation phenomena and as a
consequence it can be used for studying dynamical behavior of semiconductor
lasers and amplifiers. However, many authors use non-entirely correct ways for
the application of the method. In this paper the versatile model is proposed
for the investigation, optimization, and the control of parameters of the
semiconductor lasers and optical amplifiers which may be employed for the
creation of new generations of the high-density photonic systems for the
information processing and data transfer, follower and security arrangements.
The model is based on the coupled Schredinger, Poisson and drift-diffusion
equations which allow to determine energy quantization levels and wave
functions of charge carriers, take into account built-in fields, and to
investigate doped MQW structures and those under external electric fields
influence. In the paper the methodology of computer realization based on our
model is described. Boundary conditions for each equation and consideration of
the convergence for the method are included. Frequently encountered in practice
approaches and errors of self-consistent computations are described. Domains of
applicability of the main approaches are estimated. Application examples of the
method are given. Some of regularities of the results which were discovered by
using self-consistent method are discussed. Design recommendations for
structure optimization in respect to managing some parameters of AMQW
structures are given.Comment: 12 pages, 2 table, 4 figures, Optics East Symposium, Conference on
Physics and Applications of Optoelectronic Devices, October 25-28, 2004,
Philadelphia, Pennsylvania, US
Semiconductor THz Lasers and Their Applications in Spectroscopy of Explosives
Recently, applications of THz spectroscopy for detecting explosive agents have attracted much attention due to following reasons: many CBRNE agents have fingerprint-like features in the THz wavelength range; the THz spectroscopy provides an ability for remote and non-destructive identification of explosives; the THz radiation penetrates through many covering dielectric materials including paper, leather, fabric and so on. One of the most important components of THz spectroscopy setups is the source of THz radiation, which has to be high-power, tunable, low-cost and to have compact sizes. In this chapter, we are going to overview recent progress of wide variety of THz emitters considered as candidates for that role. We will pay a special attention to recent trends in engineering of spectral characteristics of THz quantum-cascade lasers and their tunability. Also we will describe the advantages and difficulties that accompany a THz spectroscopy of explosives
Influence of parameters of barrier stratums to a drop of a threshold current in infra-red QW lasers
Applicability of the piecewise-linear approximation of the potential profile of undoped MQW heterostructures
How to restrain Auger recombination predominance in the threshold of asymmetric bi-quantum-well lasers
Both radiative and nonradiative processes which occur in the active region of GaInAs–GaInAsP–InP asymmetric multiple quantum-well
(AMQW) heterolasers with two quantum wells of different width (4 and 9 nm) are described. Several possible processes of non-radiative
Auger recombination which affect the temperature sensitivity of the lasing threshold are analyzed and the temperature dependencies of the
investigated processes are presented. For the above-mentioned AMQW heterostructure, it is shown that the influence of the Auger
recombination processes on the temperature behaviour of the lasing threshold can be restrained by operation at temperatures lower than
340 K and the cavity losses which do not exceed 60 cm-1
Auger Recombination Processes and Threshold Conditions in Asymmetric-Multiple-Quantum-Well Heterostructure Lasers
Different possible processes of non-radiative Auger recombination which occur in the active region
of quantum-well lasers are analyzed and the temperature dependence of the lasing threshold in the
GaInAs-GaInAsP-InP bi-quantum-well heterolasers with different widths of the quantum wells (4 and 9 nm) is
determined. Activated behavior of the Auger recombination is mentioned and respective effective parameters
of the processes are calculated. For described asymmetric quantum-well heterostructure lasers, it is shown that
the influence of the Auger recombination processes on the temperature behavior of the lasing threshold is not
essential until the temperature of the active region is lower than 360 K and the cavity losses do not exceed
80 cm-
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