Novel technique for the systematic measurement of gain, absolute refractive index spectra, and other parameters of semiconductor lasers

2000 ◽  
Vol 36 (6) ◽  
pp. 721-727 ◽  
Author(s):  
L. Wu ◽  
L. Fu
Keyword(s):  
Refractive Index ◽  
Semiconductor Lasers ◽  
Systematic Measurement ◽  
Novel Technique ◽  
Absolute Refractive Index

High-accuracy interferometer with a prism pair for measurement of the absolute refractive index of glass

2009 ◽  
Vol 48 (11) ◽  
pp. 2045 ◽  
Author(s):  
Yasuaki Hori ◽  
Akiko Hirai ◽  
Kaoru Minoshima ◽  
Hirokazu Matsumoto
Keyword(s):  
Refractive Index ◽  
High Accuracy ◽  
Absolute Refractive Index ◽  
The Absolute ◽  
Prism Pair

Influence of the refractive index nonlinearity on the dynamics of emission from semiconductor lasers

1972 ◽  
Vol 1 (6) ◽  
pp. 600-605 ◽  
Author(s):  
R G Allakhverdyan ◽  
V N Morozov ◽  
A N Oraevskii ◽  
A F Suchkov
Keyword(s):  
Refractive Index ◽  
Semiconductor Lasers

scholarly journals Role of Dislocations in the Process of Degradation of Semiconductor Lasers with Electronic Energy Pumping. Experimental Research

2020 ◽  
Vol 19 (6) ◽  
pp. 507-511
Author(s):  
A. S. Garkavenko ◽  
V. A. Mokritsky ◽  
O. V. Maslov ◽  
A. V. Sokolov
Keyword(s):  
Refractive Index ◽  
Laser Radiation ◽  
Semiconductor Lasers ◽  
Electronic Energy ◽  
The Self ◽  
Generation Threshold ◽  
Degradation Processes ◽  
Energy Pumping ◽  
Self Focusing ◽  
Non Equilibrium

Light self-destruction-degradation of the second type has been observed in samples of semiconductor lasers with electronic  energy  pumping with high  optical  homogeneity and good quality of surface treatment.  In these  samples,  damage appeared in the form of cords perpendicular to the ends of the resonator. According to the current understanding of the passage of powerful light streams through various media, the emergence of narrow light channels is due to the phenomenon of self-focusing. It refers to the fundamental physical mechanisms of propagation of laser radiation and is caused by nonlinear phenomena arising in a medium under the influence of high-power laser radiation. The physical reason for self-focusing is an increase in the refractive index n in a strong light field. Thermal self-focusing is the most probable cause of radiation redistribution in the active region of the crystal. However, it is possible that in the initial stage of the appearance of light channels a certain role is played by the growth of the intensity of radiation in certain sections of the crystal because of the instability of generation or small fluctuations in the pump current density. Then the process acquires an avalanche character, since the localization of the ray in the channel increases the density of light radiation which can lead to overheating of the substance and the activation of the thermal self-focusing mechanism. The experiments performed in this paper have shown that optically homogeneous crystals possess maximum resistance to degradation processes. In them,  the critical power of light destruction is determined by the self-focusing threshold of radiation in a material. Since the nonlinear addition to the refractive index Δn = n2E2 at the self-focusing threshold is determined by the change in the concentration of non-equilibrium carriers ΔN(E2), the value of the maximum fluctuation DΔNmax itself is proportional to the value of the non-equilibrium carrier concentration at the generation threshold ΔNpores and the relative excess of the generation threshold J = (j – jn)/jn. Thus, a low threshold concentration of non-equilibrium carriers is one of the conditions for increasing material resistance to degradation processes. In doped crystals ΔNpores is less than in  pure materials. This, perhaps, explains the rather higher value of Pcritial  in the optimally doped homogeneous n-GaAs. Smaller values of Pcritial in p-type samples doped with zinc can be associated not only with the inhomogeneity of these crystals, but also with large generation thresholds. In addition, the cross section for absorption of radiation by holes is about 3–4 times larger than by electrons, which can also reduce the self-destruction threshold of lasers. At Т = 300 K, the lasing thresholds are higher that naturally reduces the value of the self-focusing threshold.

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