Abstract: A wavelength tuneable external-cavity laser module comprises a gain medium in thermal contact with a thermally stabilized substrate; an end mirror, and a phase element for controlling the phase of the optical beam and being positioned within the external cavity between the gain medium and the end mirror, wherein said phase element comprises a material having a refractive index that varies in response to changes in temperature and has a transmissivity substantially independent of wavelength across said predetermined wavelength range. The thermally-controllable phase element is configured so as to induce a phase variation that compensates the drop in the output power due to ageing or to external temperature variation. A heating element is placed in thermal contact to the phase element. By thermally controlling an intra-cavity phase element it is possible to vary continuously the output power as a function of the injection current.

Abstract: The present invention relates to a wavelength tuneable external-cavity laser module, the laser being tuneable across a predetermined wavelength range and comprising: a thermally stabilised substrate; a gain medium for emitting an optical beam passing through the external cavity along an optical axis, said gain medium being placed in thermal contact with the thermally stabilised substrate; an end mirror for receiving and reflecting the optical beam within the external cavity, and a phase element for controlling the phase of the optical beam and being positioned within the external cavity between the gain medium and the end mirror, wherein said phase element comprises a material having a refractive index that varies in response to changes in temperature and has a transmissivity substantially independent of wavelength across said predetermined wavelength range.