| abstract |
There is disclosed an improved optical device (110), such as a laser, modulator, amplifier, switch, ore the like. The invention provides an optically active device (110) comprising: an optically active region (150) having an input / output end (165); and an optically passive region (155, 160) extending from said input / output end (165, 170) of the optically active region (150) to an input / output end (175, 180) of the device (110). |