Small‐signal response of a semiconductor laser with inhomogeneous linewidth enhancement factor: Possibilities of a flat carrier‐induced FM response

1985 ◽  
Vol 46 (3) ◽  
pp. 223-225 ◽  
Author(s):  
O. Nilsson ◽  
Y. Yamamoto
Keyword(s):  
Semiconductor Laser ◽  
Enhancement Factor ◽  
Small Signal ◽  
Linewidth Enhancement Factor ◽  
Signal Response ◽  
Linewidth Enhancement

scholarly journals Effect of linewidth enhancement factor (LEF) on routes to chaos in optically injected semiconductor lasers

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
N.M. Al-Hosiny
Keyword(s):  
Semiconductor Laser ◽  
Semiconductor Lasers ◽  
Enhancement Factor ◽  
Period Doubling ◽  
Bifurcation Diagrams ◽  
Linewidth Enhancement Factor ◽  
Routes To Chaos ◽  
Linewidth Enhancement

The effect of the linewidth enhancement factor (LEF) or α-factor on two common routes to chaos (mainly period-doubling and quasi-periodic routes) in optically injected semiconductor laser is theoretically investigated using bifurcation diagrams. The value of the LEF is slightly modified to examine the sensitivity of routes to chaos to any variation in the LEF. Despite the fact that LEF enhances chaos in the system, both routes are found to be highly insensitive to the variation in the LEF.

Electronic Structure Engineering of the Linewidth Enhancement Factor in Mid-Infrared Semiconductor Laser Active Regions

1999 ◽  
Vol 607 ◽  
Author(s):  
Michael E. Flatté ◽  
J.T. Olesberg ◽  
T.F. Boggess
Keyword(s):  
Electronic Structure ◽  
Semiconductor Laser ◽  
Enhancement Factor ◽  
Gain Spectrum ◽  
Mid Infrared ◽  
Linewidth Enhancement Factor ◽  
Differential Gain ◽  
Linewidth Enhancement ◽  
Structure Engineering ◽  
Peak Gain

AbstractThe linewidth enhancement factor is a fundamental parameter that characterizes the limit of spectral purity and the tendency for filamentation in a semiconductor laser. For either narrow-line or high-power operation, it is generally desirable that the linewidth enhancement factor be minimized. This parameter depends primarily on the shape of the differential gain spectrum of the active region material. In mid-infrared laser materials, band structure engineering has been used routinely to minimize the effects of nonradiative recombination. This same approach can be used to tailor the differential gain spectrum of these materials to minimize the linewidth enhancement factor.Favorable features of the electronic structure of the material include 1) band-edge dispersion in the conduction band which shifts the peak of the gain away from the band edgeCand 2) intersubband absorption resonances, which can be designed to lie above the peak gain in energy. Both of these strategies shift the peak of the differential gain closer to the peak gain, and thus reduce the linewidth enhancement factor. These electronic structure design strategies can be used to reduce the linewidth enhancement factor in type-II InAs/GaInSb systems to almost 1.0, which is significantly smaller than typical values of 2.5–5 in type-I strained quantum wells. We note that a linewidth enhancement factor close to 1 is much smaller even than a typical linewidth enhancement factor in visible or near-infrared semiconductor lasers. Furthermore in some materials the peak of the differential gain lies in a region of positive gain, indicating that a grating could be used to select a mode with negligible linewidth enhancement factor.

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