Decreasing the threshold current density in Si lasers fabricated by using dressed-photons

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
H. Tanaka ◽  
T. Kawazoe ◽  
M. Ohtsu ◽  
K. Akahane
Keyword(s):  
Spontaneous Emission ◽  
Current Density ◽  
Optical Gain ◽  
Gain Coefficient ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Annealing Process ◽  
Optical Confinement ◽  
Light Waveguide ◽  
Soi Technology

Abstract:We fabricated a silicon (Si) laser by applying a dressed-photon–phonon assisted annealing process to a ridge-type light waveguide that we fabricated via siliconon- insulator (SOI) technology. We also evaluated a nearinfrared Si photodiode having optical gain to estimate the differential gain coefficient for designing lightwaveguides. We designed light waveguides having a thickness of 15 μm to realize a large optical confinement factor. The fabricated Si laser oscillated at a wavelength of 1.4 μm. The intensity of amplified spontaneous emission (ASE) lightwas too low to be observed, because the threshold current density was so low that the Si laser started oscillating immediately after ASE occurred. The threshold current density for oscillation was estimated to be 40 A/cm

scholarly journals Numerical Design and Frequency Response of all group-IV alloys based MQW Transistor Laser

2021 ◽  
Author(s):  
Ravi Ranjan ◽  
Prakash Pareek ◽  
Mukul Kumar Das ◽  
Saurabh Kumar Pandey
Keyword(s):  
Frequency Response ◽  
Current Density ◽  
Multiple Quantum Well ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Photon Density ◽  
Multiple Quantum ◽  
Optical Confinement ◽  
Modal Gain ◽  
Transistor Laser

Abstract In this work, a theoretical model is developed for n-p-n mid-infrared transistor laser (TL) with strain-balanced Ge0.85Sn0.15 multiple quantum well (MQW) structure in the base. Variation of optical confinement factor, modal gain and threshold current density have been rigorously investigated for different number of QWs (N) in MQW structure. The result shows that overall optical confinement factor and modal gain increase with N. The frequency response of MQWTL for common base (CB) configuration is estimated from small signal relationship between the photon density and emitter current density by solving laser rate equation and continuity equation considering the virtual states as a conversion mechanism. Increment of N causes modulation bandwidth to initially increase and then decreases with N, which reveals a shifting of device nature for higher values of N. The results also suggest that on judicious selection of N, the proposed device can become a viable monolithic light source.

Analysis of Radiative Recombination and Optical Gain in Gallium Nitride-Based Heterostructures

1996 ◽  
Vol 421 ◽  
Author(s):  
Petr G. Eliseev ◽  
Vladimir A. Smagley ◽  
Marek Osiński
Keyword(s):  
Gallium Nitride ◽  
Theoretical Calculation ◽  
Current Density ◽  
Radiative Recombination ◽  
Optical Gain ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Minimum Threshold ◽  
Effective Masses ◽  
Emitting Lasers

AbstractThreshold current density in GaN-based UV double-heterostructure lasers is predicted in the range of 2- 4 kA/cm2 using theoretical calculation of optimized heterostructure for various types of devices. Freecarrier (FC) and Coulomb-enhancement (CE) models are compared. Results are given for different combinations of effective masses. The minimum threshold current is not strongly influenced by the choice of effective masses. The FC model predicts lower than CE threshold in edge-emitting lasers, whereas the CE model predicts lower than EC threshold in thin VCSEL devices.

scholarly journals Performance characteristics of GaN/Al0.2Ga0.8N quantum dot laser at L=100Å

2018 ◽  
Vol 65 (1) ◽  
pp. 38
Author(s):  
Halima Bouchenafa ◽  
Boucif Benichou ◽  
Badra Bouabdallah
Keyword(s):  
Quantum Dot ◽  
Semiconductor Lasers ◽  
Current Density ◽  
Matrix Theory ◽  
Optical Gain ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Low Threshold ◽  
P Type ◽  
Density Matrix Theory

In this paper, a theoretical model is used to study the optical gain characteristics of  quantum dot lasers. The model is based on the density matrix theory of semiconductor lasers with relaxation broadening. The effect of doping with varying the side lengths of the box in the structure is taken into account. A comparative study of the gain spectra of p-doped, undoped and n-doped structures of  cubic quantum-dot (QD) laser respectively, is presented for various side lengths. The variation of peak gain on carrier density is also presented. The effect of side length on the variation in modal gain versus current density is plotted too. The results indicate that the p type doping is efficient to reach a better optical gain value, and to achieve low threshold current densities compared with undoped and  n-doped structures, and the optimum value for quantum dot width to achieve the lower threshold current density for the three cases is L=100A .   

scholarly journals Рабочие характеристики полупроводниковых лазеров на квантовых ямах в зависимости от ширины волноводной области

2021 ◽  
Vol 55 (12) ◽  
pp. 1229
Author(s):  
З.Н. Соколова ◽  
Н.А. Пихтин ◽  
С.О. Слипченко ◽  
Л.В. Асрян
Keyword(s):  
Output Power ◽  
Current Density ◽  
Optical Loss ◽  
Optical Power ◽  
Pump Current ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Operating Characteristics ◽  
Optical Confinement ◽  
Cladding Layers

Operating characteristics of semiconductor quantum well (QW) lasers are theoretically studied in terms of the thickness of the waveguide region [optical confinement layer (OCL)]. We calculate the maximum modal gain, optical confinement factor (in QW, OCL, and cladding layers), threshold current density, electron and hole densities (in QW and OCL), internal optical loss (in QW, OCL, and cladding layers), internal differential quantum efficiency, stimulated and spontaneous recombination currents, and output optical power of the laser as functions of the OCL thickness. It is shown that up to the pump current density 50 kA/cm2 the output power of the considered lasers depends only slightly on the OCL thickness in the range of thicknesses 1.5–2.8 m. This result is important for designing high brightness lasers as broadened waveguides are used in such lasers to attain low beam divergence. At high pump current densities, the output power is shown to have a maximum as a function of the OCL thickness.

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