Patent ID: 7106765
Filing Date: 2006-09-12
Classification: H01S

Abstract:
1. A tuneable laser, comprising a gain section bounded at one end by a first reflector adapted to produce a comb of reflective peaks and at the other end by a second reflector in the form of a plurality of discrete grating units each capable of reflecting at one of the peaks of the comb, and each grating unit having at least two independently actuable electrodes, which when actuated independently one from the other are capable of reducing the reflectivity of the grating unit, and wherein each grating unit has a different pitch to that of each other grating unit, the laser being arranged such that it is tuned to a desired wavelength by applying current to both of the independently actuable electrodes of one selected grating unit only, and by applying current to all of the other grating units via only one of the at least two independently actuable electrodes of each of those grating units, such that the tuneable laser lases at the wavelength to which the selected grating unit is tuned.