The Principle Experiment of AlN Used as a Non-Absorbing Window Material of LDs

Abstract

In order to reduce the catastrophic optical damage ( COD ) in the cavity surface of the traditional GaAs-LDs, this paper proposed the use of AlN film prepared as a non-absorbing window near the cavity surface of GaAs-LDs. In order to validate its feasibility, first of all, we prepared AIN film with different thickness on GaAs chips by reactive magnetron sputtering technology, and then, the PL spectroscopy of AlN / GaAs surface was acquired, the residual stress of the structure was calculated in accordance with the wavelength drift of GaAs intrinsic peak with the change in testing temperature.The experimental results show that the compression stress on GaAs chip is obvious when the thickness of AlN film is above 0.8 um. After the GaAs chip is subjected to compressive stress, the band gap will be widened,so the Eg of the active region near window area of GaAs-LDs will be wider than one of the active region inner the cavity, so that when the photons pass through this area, the absorption will be reduced, thereby forming non-absorbing window,therefore, the experimental validated that the AlN film used as the non-absorbing window of GaAs-LDs is feasibility.