Semiconductor photonic crystals for optoelectronics

Abstract

We present a number of designs for the integration of photonic crystals (PC) with active semiconductor devices. As a first step, the use of PC blocks as laser mirrors is demonstrated. Ridge-waveguide lasers with a length of 100 μm and two PC mirrors achieve threshold currents below 8 mA . In order to obtain single-mode operation, an intracavity PC mirror can be used, which effectively separates the laser into two coupled cavities. Lasing occurs where two modes of the cavities coincide, leading to single-mode operation with a side-mode suppression ratio (SMSR) of over 35 dB . We also present two full PC devices: a single-mode laser with a coupled resonant cavity waveguide (CROW) and a tunable laser. The CROW device consists of a chain of 40 hexagonal cavities formed in a block of PC, with a total length of 140 μm . Low threshold, single-mode operation with over 40 dB SMSR is demonstrated. Coupled cavities are used for the tunable PC laser, which covers a tuning range of over 30 nm .