共查询到20条相似文献,搜索用时 15 毫秒
1.
First results of our new finite-element modelling of thermal properties of GaAs/(AlGa)As buried-heterostructure (BH) lasers are reported. The calculus procedure is very efficient, so we have used a standard IBM PC/XT microcomputer. For the stripe active-region width of 1 m, the thermal resistance of the laser was determined to be about 70 KW-1, whereas its electrical resistance was about 6 ohms. To the best of our knowledge, isothermal lines within BH lasers have been obtained for the first time. The isothermal configuration enables us to analyse heat-spreading phenomena in BH lasers, which makes possible thermal optimization of the laser construction.As the first application of the model, the relative influence of the oxide layer thickness on the laser thermal resistance was examined. Because of relatively large lateral dimensions of the laser crystal as compared to the active region, this influence is often neglected, whereas our detailed calculations reveal its importance. An increase in this thickness from 0.1 m to 0.5 m is followed by over 15% increase in the laser thermal resistance. 相似文献
2.
We have developed a novel and simple passive technique to frequency lock an antireflection-coated diode laser to a power-buildup cavity. The beam reflected from a mode-mismatched cavity is spatially filtered so the maximum reflected intensity occurs at a cavity resonance. We experimentally and theoretically investigated the locking behavior and found that it is both robust and stable. In an implementation of the technique a 100-W intracavity beam can be generated by use of only a two-mirror cavity and a 15-mW 635-nm diode laser driven by a dc current. 相似文献
3.
Simple design of an edge-emitting diode laser for preventing spatial multimoding via thermal lensing
The parameters of a diode-laser structure composed of a pair of built-in high-index regions for providing stable, single-spatial-mode operation to high cw powers are numerically found. A three-dimensional numerical code has been implemented that takes into account carrier diffusion in the quantum well and thermal lensing. The laser characteristics are calculated as functions of the above-threshold drive level. Within the simulation, higher-order optical modes on a "frozen background" are computed via the Arnoldi algorithm. Then, for a 6-μm-wide low-index core and 2-3-mm-long devices, stable single-mode operation up to multiwatt-level (2-3 W) cw output power is predicted. 相似文献
4.
The Monte-Carlo model of a light-emitting diode 总被引:1,自引:0,他引:1
The first complete Monte-Carlo model of a surface light-emitting diode is presented in this paper. In the model all important phenomena (including the two-dimensional diffusion of minority carriers before their recombination in the active region and the re-emission of radiation) are taken into account. The influence of various construction parameters on the external quantum efficiency of the homojunction GaAs diode is examined. 相似文献
5.
《中国物理 B》2015,(5)
We present an accurate through silicon via(TSV) thermal mechanical stress analytical model which is verified by using finite element method(FEM). The results show only a very small error. By using the proposed analytical model, we also study the impacts of the TSV radius size, the thickness, the material of Cu diffusion barrier, and liner on the stress. It is found that the liner can absorb the stress effectively induced by coefficient of thermal expansion mismatch. The stress decreases with the increase of liner thickness. Benzocyclobutene(BCB) as a liner material is better than Si O2. However,the Cu diffusion barrier has little effect on the stress. The stress with a smaller TSV has a smaller value. Based on the analytical model, we explore and validate the linear superposition principle of stress tensors and demonstrate the accuracy of this method against detailed FEM simulations. The analytic solutions of stress of two TSVs and three TSVs have high precision against the finite element result. 相似文献
6.
We describe a simple electro-optically activated external-cavity diode laser designed to provide high-speed, high-coherence tuning over gigahertz frequency ranges. Tuning as fast as 23 GHz/ micros is demonstrated. Coherence measurements indicate transform-limited quiescent laser linewidth in observation windows as wide as ~100 micros and transform-limited chirps. A self-heterodyne, cross-correlation-based coherence diagnostic is developed for characterizing phase coherence during high-speed chirps. 相似文献
7.
A simple model based on the statistics of single atoms is developed to predict the diffusion rate of thermal atoms in (or on) bulk materials without empirical parameters. Compared with vast classical molecular-dynamics simulations for predicting the self-diffusion rate of Pt, Cu, and Ar adatoms on crystal surfaces, the model is proved to be much more accurate than the Arrhenius law and the transition state theory. Applying this model, the theoretical predictions agree well with the experimental values in the presented paper about the self-diffusion of Pt (Cu) adatoms on the surfaces. 相似文献
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10.
A novel analytical thermal model for multilevel nano-scale interconnects considering the via effect 下载免费PDF全文
Based on the heat diffusion equation of multilevel
interconnects, a novel analytical thermal model for multilevel
nano-scale interconnects considering the via effect is presented,
which can compute quickly the temperature of multilevel
interconnects, with substrate temperature given. Based on the
proposed model and the 65~nm complementary metal oxide semiconductor
(CMOS) process parameter, the temperature of nano-scale
interconnects is computed. The computed results show that the via
effect has a great effect on local interconnects, but the reduction
of thermal conductivity has little effect on local interconnects.
With the reduction of thermal conductivity or the increase of
current density, however, the temperature of global interconnects
rises greatly, which can result in a great deterioration in their
performance. The proposed model can be
applied to computer aided design (CAD) of very large-scale
integrated circuits (VLSIs) in nano-scale technologies. 相似文献
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12.
Measurement of thermal rise-time of a laser diode based on spectrally resolved waveforms 总被引:1,自引:0,他引:1
Thermal resistance and thermal rise-time are two basic parameters that affect most of the performances of a laser diode greatly. By measuring waveforms received after a spectroscope at wavelengths varied step-by-step, the spectrally resolved waveforms can be converted to calculate the thermal rise-time. Basic formulas for the spectrum variation of a laser diode and the measurement set-up by using a Boxcar are described in the paper. As an example, the thermal rise-time of a p-side up packaged short-pulse laser diode was measured by the method to be 390 μs. The method will be useful in characterizing diode lasers and LD modules in high-power applications. 相似文献
13.
The thermal diffusivity h of a thin film on a substrate is measured by using the mirage technique. The photothermal deflection of the probe beam is caused by the heat field and the substrate, heated by the pump beam. From the experimental data a two-dimensional algorithm is proposed to obtain the measurements of the diffusivity of film and substrate in one set of mirage detection. 相似文献
14.
We improved the thermal equivalent-circuit model of the laser diode module(LDM) to evaluate its thermal dynamic properties and calculate the junction temperature of the laser diode with a high accuracy.The thermal parameters and the transient junction temperature of the LDM are modeled and obtained according to the temperature of the thermistor integrated in the module.Our improved thermal model is verified indirectly by monitoring the emission wavelength of the laser diode against gas absorption lines,and several thermal parameters are obtained with the temperature uncertainty of 0.01 K in the thermal dynamic process. 相似文献
15.
W. KLodzimierz Nakwaski 《Optical and Quantum Electronics》1979,11(4):319-327
The analysis of the heat spreading in the single-heterostructure GaAs-Ga1-x Al
x
As laser diode supplied with short current pulses (in the case, however, when the adiabatic approximation is no longer valid) at room temperature is presented in this paper. Relations are derived, describing the time-dependent temperature rise within the volume of the laser diode. The calculations are carried out for a typical SH laser diode. It turns out that in the duration of the short current pulses (t
I=200 ns,j=1.5 × 104A cm–2) the increase in junction temperature of the typical SH laser diode amounts to about 6.1 K. This increase leads to an increase of about 9% in the threshold current, to a decrease of about 18% in the laser radiation intensity, and to a shift of the spontaneous radiation band and of the stimulated radiation modes of about 1.9 nm and 0.22 nm, respectively, during each current pulse. 相似文献
16.
Wang Ying-Jian 《Journal of Quantitative Spectroscopy & Radiative Transfer》1984,31(5):457-460
A theoretical model for total absorption of a band is developed based on the Elsasser band model and considering the effects of spectral band contour and low-intensity lines in the spectral band. This model yields a simple and analytical expression and has the correct asymptotic forms. Comparisons with other models are presented. 相似文献
17.
P. J. Bream J. J. Lim S. Bull A. V. Andrianov S. Sujecki E. C. Larkins 《Optical and Quantum Electronics》2006,38(12-14):1019-1027
We describe the inclusion of nonequilibrium gain into a self-consistent 2.5D CW spectral laser diode model and report on the use of this model to investigate the origin of gain compression in a 975 nm high-brightness tapered QW laser diode. Nonequilibrium gain is calculated using a dynamic gain model, which simulates the dynamic relaxation of the quantum well carrier energy distributions under the influence of steady-state electrical and optical excitation. Calculated gain and spontaneous emission spectra are included in the laser model via parameterised look up tables. Both simulated and experimentally measured intracavity spontaneous emission spectra show an increased carrier density and a blue-shift of the gain maximum with increasing bias caused by carrier heating and spectral hole burning. The accurate incorporation of nonequilibrium gain compression is therefore vital for the accurate prediction of the operating characteristics of these devices and for the experimental determination of the active region temperature. 相似文献
18.
Włodzimierz Nakwaski 《Optical and Quantum Electronics》1989,21(4):331-334
Three-dimensional thermal analysis of catastrophic mirror damage in stripe-geometry diode lasers was carried out in the present work. The spatial extent of the heat source at and near to the mirror surface as well as the temperature dependences of both the thermal conductivity and the thermal diffusivity are taken into account in the model. The heat conduction equation is solved by means of the Green function method. 相似文献
19.
A calculation of the pion balance functions in a thermal model is presented. The total result consists of resonance and non-resonance parts. A satisfactory agreement with the data on Au+Au collisions at v[sNN] = 130 GeV is found. 相似文献
20.
We give an analytical analysis to the acoustic propagation in an acoustic diode (AD) model formed by coupling a superlattice (SL) with a nonlinear medium. Analytical solutions of the acoustic transmission are obtained by studying the propagations in the SL and the nonlinear medium separately with the conventional transfer-matrix method and a perturbation technique. Compared with the previous numerical method, the proposed approach contributes a better physical insight into the intrinsic mechanism of acoustic rectification and helps us to predict the performance of an AD within the effective rectifying bands in a simple way. This is potentially significant for the practical design and fabrication of AD devices. 相似文献