Simulation of a Ridge-Type Semiconductor Laser with Transversal Diffraction Gratings

2021 ◽  
Author(s):  
Tatsuhiro Hirose ◽  
Takahiro Numai
Keyword(s):  
Semiconductor Laser ◽  
Semiconductor Lasers ◽  
Light Output ◽  
Diffraction Gratings ◽  
Transverse Mode ◽  
Type Semiconductor ◽  
Horizontal Transverse Mode

Abstract This paper reports on improvement of stability of the fundamental horizontal transverse mode in a ridge-type semiconductor laser by incorporating transversal diffraction gratings. Kinks do not appear in current versus light-output curves by appropriately designing the number of the grating periods when the mesa width is 5 μm in which kinks exist in current versus light-output curves for conventional ridge-type semiconductor lasers.

GaAs/AlGaAs photonic crystals for VCSEL-type semiconductor lasers

2011 ◽  
Vol 19 (1) ◽  
Author(s):  
R. Kruszka ◽  
M. Ekielski ◽  
K. Gołaszewska ◽  
K. Korwin-Mikke ◽  
Z. Sidor ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Semiconductor Laser ◽  
Semiconductor Lasers ◽  
Laser Structure ◽  
Type Semiconductor ◽  
Working Parameters

AbstractThe results of modelling of the influence of photonic crystal on the performance of VCSEL-type semiconductor laser structure are shown and indicate that the use of those structures would significantly improve the working parameters of the devices. The method of fabrication of photonic crystals in the Bragg mirrors of GaAs/AlGaAs-based VCSELs is presented.

scholarly journals Photocatalytic techniques to prevent and combat healthcare associated infections

2019 ◽  
Vol 111 ◽  
pp. 04046
Author(s):  
Răzvan Bucureşteanu ◽  
Roxana Apetrei ◽  
Monica Ioniţă ◽  
Ludmila-Otilia Cinteză ◽  
Lia-Mara Diţu ◽  
...  
Keyword(s):  
Light Output ◽  
Antimicrobial Effect ◽  
Light Sources ◽  
Healthcare Associated Infections ◽  
Excitation Light ◽  
Disinfection Process ◽  
Type Semiconductor ◽  
Healthcare Associated ◽  
Areas Of Interest ◽  
Air Circulation

An ever-increasing rate of morbidity and mortality caused by healthcare associated infections is reported annually. Air circulation mediates contact with microbial contaminated aerosols and represents a major risk of transmitting healthcare associated infections. We propose a revolutionary technique for the protection of interior surfaces based on a photocatalytic composition with doped TiO2 or ZnO type semiconductor metal oxides which exert antimicrobial effect. In principle, there is an activation of the photocatalytic coating with light from the normal lighting apparatus, which may incorporate one or more sources of photocatalytic excitation light. By studying the air circulation in the hospital, it is possible to design light fixtures with specific design of light distribution, in order to perform the disinfection of the air and surfaces and to amplify the antimicrobial effect. The disinfection process does not affect patients or healthcare professionals, it can be done in their presence and has a continuous, controllable effect. Photocatalytic paint in combination with a prototype luminaire with a precise spectrum light sources, light output and a light intensity distribution curve relative to the shape and dimensions of the rooms, shows that the proposed method may represent a successful alternative to classical methods of disinfection in hospitals. This technique can also be used in other areas of interest.

Linewidth Stabilization of Semiconductor Lasers in an External Cavity

1984 ◽  
Vol 5 (2) ◽  
Author(s):  
C. J. Nielsen ◽  
J. H. Osmundsen
Keyword(s):  
Semiconductor Laser ◽  
Semiconductor Lasers ◽  
Cavity Mode ◽  
External Cavity ◽  
Frequency Stabilization ◽  
Control Loop ◽  
Mean Frequency ◽  
Mode Operation ◽  
Single Cavity ◽  
Single Cavity Mode

SummaryAn automatic linewidth control loop which provides stable optimum linewidth reduction and single cavity mode operation of an external cavity semiconductor laser is presented. Stable linewidth reduction from 70 MHz to below 2 MHz is obtained for a 1.3 μm BH-laser, whereas simultaneous mean frequency stabilization to within 1 kHz and linewidth reduction from 17 MHz to 1.6 MHz is demonstrated for an 830 nm CSP-laser.

Tuning of external-cavity semiconductor lasers with chirped diffraction gratings

2005 ◽  
Vol 44 (24) ◽  
pp. 5112 ◽  
Author(s):  
Marc Duval ◽  
Gilles Fortin ◽  
Michel Piché ◽  
Nathalie McCarthy
Keyword(s):  
Semiconductor Lasers ◽  
External Cavity ◽  
Diffraction Gratings ◽  
External Cavity Semiconductor Lasers

Optical bistability in semiconductor lasers

1984 ◽  
Vol 313 (1525) ◽  
pp. 333-340 ◽  
Keyword(s):  
Semiconductor Lasers ◽  
Optical Bistability ◽  
Light Output ◽  
Optical Signal ◽  
Current Drive ◽  
Simple Circuit ◽  
Optical Logic ◽  
Flip Flop ◽  
Injection Lasers ◽  
Circuit Analogy

Absorptive, dispersive and modal bistabilities are considered in semiconductor injection lasers. Previous work is briefly reviewed and the discussion is concerned with experimental work with transverse modal bistability in twin stripe injection lasers. A simple circuit analogy indicates how modal bistability can arise and how it is possible to have stronger light output on the side where the current drive is weakest. Experimental results are reviewed for an optical flip-flop with the use of twin-stripe lasers with three such lasers coupled together in an optical logic circuit. Various mode patterns that have been observed by using different geometries of twin-stripe lasers are discussed. Use is foreseen for active bistable devices in front-end optical signal processing.

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