Abstract

There is much interest in monolithically integrated multiwavelength laser sources for applications in wavelength-division-multiplexed (WDM) communication systems. To date, two-dimensional integrated-optics techniques have been implemented by using both focusing gratings¹ and wavelength routers² to allow laser emission with precise wavelength registration. However, at present the modulation rates available from such devices are limited to around 200 Mbit/s. In this paper we report a new design for a monolithically integrated multichannel laser based on the multichannel grating cavity laser,³ which is predicted to allow modulation rates of up to 5 Gbit/s per spectral channel. This laser, illustrated in Fig. 1, uses a transmission grating formed in a slab heterostructure waveguide and is configured so that incidence angles on all reflective elements are greater than the critical angle. This minimizes reflection losses. A laser cavity is formed between each reflector waveguide and the common output waveguide through the mirror and grating structures. The channel separation is determined by the linear dispersion of the grating- mirror combination and the center-to-center separation of the reflector waveguides.

© 1995 Optical Society of America