Spectrally shaped tunable short-cavity laser

A tunable laser operative to emit tunable radiation over an emission wavelength range having a center wavelength, with an output power spectrum having a target spectral shape over said wavelength range and an average emission power, said tunable laser comprising:

• an optical cavity including a first and second mirror;
• a gain region interposed between said first and second mirrors;
• a tuning region;
• means for adjusting an optical path length of said tuning region to create wavelength tuning of said tunable laser;
• and
• an optical amplifier having an amplified spontaneous emission (ASE) spectrum;
• wherein:
• a free spectral range (FSR) of said optical cavity exceeds 5% of said center wavelength;
• said tunable laser operates in a single longitudinal and transverse mode over said wavelength range;
• and
• an alignment of said ASE spectrum relative to said emission wavelength range is controlled to achieve said target spectral shape.

A method for generating an output power variation versus wavelength over a wavelength range from a tunable laser operative to emit tunable radiation over an emission wavelength range having a center wavelength, with an output power spectrum over said wavelength range and an average emission power, said tunable laser comprising:

• an optical cavity including a first and second mirror;
• a gain region interposed between said first and second mirrors;
• a tuning region;
• and means for adjusting an optical path length of said tuning region;
• wherein:
• a free spectral range (FSR) of said optical cavity exceeds 5% of said center wavelength;
• and said tunable laser operates in a single longitudinal and transverse mode over said wavelength range;
• the method comprising dynamically controlling a pump energy entering into the gain region versus wavelength during wavelength tuning.

A method for generating a desired output power variation versus wavelength over a wavelength range from a tunable laser operative to emit tunable radiation over an emission wavelength range having a center wavelength, with an output power spectrum over said wavelength range and an average emission power, said tunable laser comprising:

• an optical cavity including a first and second mirror;
• a gain region interposed between said first and second mirrors;
• a tuning region;
• and means for adjusting an optical path length of said tuning region;
• wherein:
• a free spectral range (FSR) of said optical cavity exceeds 5% of said center wavelength;
• and said tunable laser operates in a single longitudinal and transverse mode over said wavelength range;
• the method comprising defining a target power variation over the wavelength range, and adjusting a reflectivity spectrum of one of said first and second mirrors until said output power variation matches said target power variation over the wavelength range.