Wavelength stabilized light emitter and system for protecting emitter from backreflected light

A method for operating a gain module, the gain module comprising

• a gain medium operative to emit a broad-spectrum light along an optical axis, and
• a spectrally-selective element configured with a one-piece slob of photosensitive material and two parallel feedback and isolating Bragg mirrors, wherein the feedback mirror provides a wavelength-dependent feedback into the gain medium lasing a laser light at a desired wavelength, and an isolating Bragg mirrors,
• the method comprising displacing the spectrally-selective element to a desired position in which:
• the feedback Bragg mirror provides the wavelength-dependent feedback, and
• the isolating Bragg mirror retroreflects a backreflected signal light originated downstream from the spectrally selective element.

A laser system, comprising:

• at least one gain block radiating a signal light;
• and
• a gain module outputting a laser light at a desired wavelength in a desired position, the laser light being coupled into the gain block, the gain module having:
• a laser chip generating a broad spectrum light;
• and
• a one-piece spectrally-selective element located between the laser chip and gain block and configured with:
• a sole slab of transparent material,
• a feedback Bragg mirror (FBM) recorded in the slab and operative to provide an optical feedback to the laser chip so that the laser chip radiates the laser light at the desired wavelength, and
• an isolating Bragg mirror (IBM) recorded in the slab parallel to and downstream from the FBM and operative to retroreflect the signal light which is backreflected from the gain block.