Apparatus and method for stabilizing wavelength tunable laser

An apparatus configured to stabilize an output of a laser, the apparatus comprising:

• a Fabry-Perot filter configured to filter light amplified by a semiconductor optical amplifier having the first wavelength band and provide light having a second wavelength band narrower than a first wavelength band;
• a fiber Bragg grating (FBG) configured to amplify a portion of the light having the second wavelength band provided from the Fabry-Perot filter to generate a reference signal;
• and
• a controller configured to maintain a differential of 1) a time difference between a laser modulation signal corresponding to a criterion for selecting the second wavelength band and the reference signal provided by the FBG, and 2) a difference in an oscillation time in a predetermined range of a normal operation of the laser to be less than a predetermined criterion by adjusting an offset of the Fabry-Perot filter.

A method of stabilizing an output of a laser, the method comprising:

• oscillating, by an optical amplifier, light having a first wavelength band, based on a laser modulation signal;
• filtering, by a filter, the light having the first wavelength band to provide light having a second wavelength band narrower than the first wavelength band;
• amplifying, by a reference signal generator, at least a portion of the light having the second wavelength band to generate a reference signal;
• and
• controlling, by a controller, the filter to stabilize a wavelength center of the output of the laser by performing feedback of a time difference between the laser modulation signal and the reference signal.

A method of stabilizing an output of a laser, the method comprising:

• filtering, by a Fabry-Perot filter, light amplified by a semiconductor optical amplifier having the first wavelength band to provide light having a second wavelength band narrower than a first wavelength band;
• amplifying, by a fiber Bragg grating (FBG), a portion of the light having the second wavelength band provided from the Fabry-Perot filter to generate a reference signal;
• and
• controlling, by a controller, the laser modulation signal by performing feedback of a time difference between the reference signal and the laser modulation signal.

A non-transitory computer-readable recording medium comprising a program including instructions which when executed by a processing device using the program causes the processing device to:

• control an optical amplifier to oscillate light having a first wavelength band in response to a laser modulation signal;
• receive from reference signal generator at least a portion of light having a second wavelength band amplified to generate a reference signal;
• and
• control a filter filtering the light having the first wavelength band to provide the light having the second wavelength band narrower than the first wavelength band to stabilize a wavelength center of the output of the laser using feedback of a time difference between the laser modulation signal and the reference signal.