No abstract

A useful closed-form expression for stresses within individual layers of a multilayer composite has been obtained as a function of position within the layer. Equal and isotropic elastic constants were assumed in the calculation, although the error introduced by this assumption is found to vary by no more than the difference in elastic constants. Unequal elastic constants may be handled via computer solutions. The stresses within heterojunction AlxGa1−xAs/GaAs lasers are calculated as an example of the technique. The addition of Al to the active GaAs region is shown to have a drastic effect upon the active-region stress, changing it from tension to compression. This change of sign in stress is correlated with improvements in operating lifetimes of lasers.

Mid-infrared (λ=3.25 μm) broadened-waveguide diode lasers with active regions consisting of 5 type-II “W” quantum wells operated in continuous-wave (cw) mode up to 195 K. At 78 K, the threshold current density was 63 A/cm2, and up to 140 mW of cw output power was generated. A second structure with ten quantum wells operated up to 310 K in pulsed mode.

This paper describes the dark current properties of In,Gal-,As photodiodes, where s is varied from 0.53 to 0.82 for extending the long wavelength cutoff from 1.7 to 2.6 pm. Detailed analyses of optoelectrical parameters of Ino x2Gao lkAs photodiodes are presented. Dark current, which is a critical parameter and limits the operation of the photodiode, is analyzed and compared with the experimental values. Typical characteristics of photodiodes with cutoff wavelengths of 1.7 pm(s = 0.33), 2.2 pm(s = 0.72), and 2.6 pm(.r = 0.82) are presented. Typical and best values of dark current obtained are presented.

No abstract

Published by the AIP PublishingArticles you may be interested in Room temperature continuous wave operation of quantum cascade lasers with watt-level optical power Gain and loss in an optically pumped mid-infrared laser

Experimental evidence for unidirectional cracking in III-V compounds is presented. The crack direction is shown to be a function of the sign of the applied stress and follows the asymmetry of the zinc blende structures. The critical stress for cracking in InGaP/GaAs in tension was found to be E/680 (--,4.5 • 109 dynes/cm2). Cracks in InGaP and GaAsP grown on GaAs substrates are related to the zinc blende asymmetry with the aid of Sirtl's etch. A fracture mechanism which introduces asymmetric dislocations into the Cottrell fracture mechanism is advanced. Asymmetries in elastic bending ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.132.123.28 Downloaded on 2015-07-10 to IP Vol. I21, No. 12 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.132.123.28 Downloaded on 2015-07-10 to IP

No abstract