SAMPLED GRATING DISTRIBUTED REFLECTOR LASER

摘要

A sampled grating distributed reflector laser comprises an active section (2), a phase section (8) and at least one sample grating section (4, 6). The or each sample grating section comprises a plurality of grating bursts distributed along the optical axis of the section such that the section exhibits a comb of reflection maxima and is such that the application of a respective electrical current (iF, iR and iphase) to the at least one grating section (4, 6) and phase section (8) shifts the wavelength of the comb and changes the effective cavity length of the laser thereby enabling tuning of the laser. The laser is characterised in that the at least one grating section (4, 6) is provided with an electrode (12, 16) which comprises a plurality of electrical contacts (20a-20d, 22a-22d) which overly a respective grating burst. The dimensions of the contacts (20a-20d, 22a-22d) are selected such that electrical current is substantially localised to the grating bursts.