| Prior to 1991, the most advanced tunable semiconductor laser was the "Distributed Bragg Reflector" or DBR laser. The tuning limitation in DBR lasers is a cavity design which constrains the fractional wavelength tuning ;This dissertation describes a new type of tunable semiconductor laser, which can have a tuning range ;The first chapter of this dissertation is devoted to describing the history of tunable semiconductor lasers. The next two chapters describe the theory of sampled gratings and the tuning properties of lasers employing them. The following two chapters describe fabrication and device results. In particular, in Chapter 5, we describe tunable lasers with 10 mW output power, tuning ranges over 70 nm, and single-frequency operation with very large suppression of spurious laser cavity modes. Chapter 6 summarizes, and concludes with some suggestions for improving device performance and exploring new geometries. |
