Spectral linewidth broadening due to self‐modulation of the refractive index of semiconductor lasers

1985 ◽  
Vol 47 (6) ◽  
pp. 562-564 ◽  
Author(s):  
H. Sato ◽  
T. Fujita
Keyword(s):  
Refractive Index ◽  
Semiconductor Lasers ◽  
Spectral Linewidth ◽  
Linewidth Broadening

Single-molecule spectromicroscopy: a route towards sub-wavelength refractometry

2015 ◽  
Vol 184 ◽  
pp. 263-274 ◽  
Author(s):  
T. A. Anikushina ◽  
M. G. Gladush ◽  
A. A. Gorshelev ◽  
A. V. Naumov
Keyword(s):  
Refractive Index ◽  
Single Molecule ◽  
Low Temperatures ◽  
Radiative Lifetime ◽  
Spatially Resolved ◽  
Local Fluctuations ◽  
Novel Approach ◽  
Spectral Linewidth ◽  
Spatial Fluctuations ◽  
Sub Wavelength

We suggest a novel approach for spatially resolved probing of local fluctuations of the refractive index n in solids by means of single-molecule (SM) spectroscopy. It is based on the dependence T1(n) of the effective radiative lifetime T1 of dye centres in solids on n due to the local-field effects. Detection of SM zero-phonon lines at low temperatures gives the values of the SM natural spectral linewidth (which is inversely proportional to T1) and makes it possible to reveal the distribution of the local n values in solids. Here we demonstrate this possibility on the example of amorphous polyethylene and polycrystalline naphthalene doped with terrylene. In particular, we show that the obtained distributions of lifetime limited spectral linewidths of terrylene molecules embedded into these matrices are due to the spatial fluctuations of the refractive index local values.

Spectral linewidth reduction in semiconductor lasers by an external cavity with weak optical feedback

1983 ◽  
Vol 19 (22) ◽  
pp. 938 ◽  
Author(s):  
E. Patzak ◽  
H. Olesen ◽  
A. Sugimura ◽  
S. Saito ◽  
T. Mukai
Keyword(s):  
Semiconductor Lasers ◽  
Optical Feedback ◽  
External Cavity ◽  
Spectral Linewidth

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

Calculation of spectral linewidth reduction of external-cavity strong-feedback semiconductor lasers

1994 ◽  
Vol 33 (21) ◽  
pp. 4771 ◽  
Author(s):  
Haiyin Sun ◽  
Steve Menhart ◽  
Alois Adams
Keyword(s):  
Semiconductor Lasers ◽  
External Cavity ◽  
Spectral Linewidth

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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