The new design of high power laser diodes, based on partly phase-locked laser arrays was developed in this work. The high temporal and spatial stability of such design laser diodes make them more preferable for high stable diode- pumped solid-state lasers than broad-area stripe contact laser diodes. Furthermore, the long lifetime of laser diodes with partly phase-locked array permits to use them in the field of material processing and medical applications.
We report on the influence of the different specifications of a single emitter laser diode (type A) and a laser diode (LD) of the partially phase locked type (type B), on some characteristics of our diode pumped solid state lasers (DPSSL). We find that the use of the type B LD is preferable to that of type A with respect to smaller M2 of the DPSSL-beam, superior noise behavior, and smaller full width at half maximum of the LD emission.
In this paper we present the calculation of local mirror facet overheating of the SCH laser diode active region. It is shown that optical strength of the mirror facet prior to optical damage depends on optical confinement factor ((Gamma) -factor) and thickness of the active region layer adjacent to surface (`dead layer') where nonradiative recombination rate is much higher. Detailed investigations of local mirror facet temperature and optical strength of mirror facet in both Al-containing (AlGaAs/GaAs, InGaAs/AlGaAs/GaAs) and Al-free (InGaAsP/GaAs) single quantum well laser diodes were carried out. Experimental results are in good agreement with calculations. It is shown that optical strength of mirror facet for laser heterostructure can be derived from the behavior of local mirror facet overheating of laser diodes.
We studied local facet temperature near the active region of high power SCH SQW InGaAsP/GaAs (0.8 micrometers ) and InGaAs/GaAs (0.98 micrometers ) laser diodes (LD) along with their optical and degradational characteristics. It was shown that facet overheating with respect to the bulk temperature of the LD for current densities J < 2000 A/cm2 was due to the absorption of intrinsic radiation of the LD and nonradiative recombination of nonequilibrium carriers at the mirror facets, while for J > 2000 A/cm2 facet overheating connected with the surface leakage current was observed. Either mechanism may dominate in limiting the maximum optical power as well as increase the degradation rate of the LD.