Tunable laser with suppression of spontaneous emission

A laser apparatus, comprising:

• (a) a gain medium having first and second facets, said gain medium emitting a light beam from said first facet along an optical path;
• (b) a reflector positioned in said optical path, said reflector and said second facet of said gain medium defining an external laser cavity;
• (c) a tuning element positioned in said optical path and configured feed back light of a selected wavelength to said gain medium, said tuning element defining a first output beam traveling a first output path;
• (d) a beam coupler positioned in said optical path and configured to create a second output beam from light directed from said tuning element to said beam coupler, said second output beam traveling along a second output path that is parallel to said first output path;
• and
• (e) said second output beam having a spontaneous emission component that is spatially separated from said selected wavelength by operation of said tuning element on said second output beam.

A method for laser operation, comprising:

• (a) emitting a light beam from a gain medium along an optical path;
• (b) feeding light of a selected wavelength back to said gain medium by a tuning element positioned in said optical path;
• (c) creating a first output beam by said tuning element, said first output beam directed along a first output path;
• (d) creating a second output beam by a partial reflector positioned in said optical path to receive light of said selected wavelength from said tuning element, said second output beam directed along a second output path parallel to said first output path;
• and
• (e) spatially separating spontaneous emission light from light of said selected wavelength in said second output beam.

A method for laser operation, comprising:

• (a) providing a reflector and a gain medium having front and rear facets, said reflector and said rear facet defining an external laser cavity;
• (b) emitting a light beam from said front facet of said gain medium along an optical path, said reflector positioned in said optical path
• (c) positioning a tuning element in said optical path;
• (d) creating a first output beam that exits said external laser cavity along a first output path;
• (e) creating a second output beam that exits said external laser cavity along a second output path parallel to said first output path;
• and
• (f) spatially separating spontaneous emission light from light of said selected wavelength in said second output beam.

A laser apparatus, comprising:

• (a) means for emitting a light beam along an optical path;
• (b) tuning means for feeding light of a selected wavelength back to said emitting means;
• (c) means for forming a first output beam and directing said first output beam along a first output path;
• (d) means for forming a second output beam from light of said selected wavelength and directing said second output beam along a second output path parallel to said first output path;
• and
• (e) means for spatially separating spontaneous emission light from light of said selected wavelength in said second output beam.