GaAlAs Window Laser with High CW Output Powers

Index guided GaAlAs laser diodes capable of providing high output powers with good beam quality are desirable for applications such as optical storage and printing. Unfortunately, the output powers of most such devices are limited to several milliwatts because of catastrophic optical mirror damage (COMD), caused by absorption of the laser output, which can exceed several MW/cm2 in intensity, at the facet. One can increase the stripe width, thereby lowering the output intensity for given overall power, as is done in such structures as the channelled substrate planar (CSP), but beyond a certain stripe width the lasing mode becomes non-fundamental, resulting in a multilobed output beam. In addition, operation close to the COMD level causes sharp degradation in reliability.