OPTICAL DEVICE

摘要

An optical device for use as an amplifier or modulator comprises a semiconductor substrate (2) with an elongate waveguide region (1) with a light guiding boundary that extends between an input (3) and an output (4) for optical radiation. An optically active layer of material (6) produces amplification of light travelling inthe waveguide region (1). The width (w) of region (1) tapers outwardly from the input to allow amplification of input optical signals, and tapers towards the output (4) so as to concentrate the amplified light in a single mode to the output. The concentration of the amplified light in the active region may produce non-linear effects which are exploited in order to achieve data modulation or switching. In one embodiment, the waveguide region includes a first active region (30) to produce optical amplification, and a second passive region (31) for concentrating light to the output.