Wavelength-tunable light source and wavelength control method for the same
AssigneeSumitomo Electric Industries, Ltd.
InventorsTomoko Miura, Katsumi Uesaka
Life of this patent
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Abstract
A wavelength-tunable light source includes a wavelength-tunable laser including a first region and a second region each of which includes at least one of heaters, a frequency locker configured to receive output light of the wavelength-tunable laser and output two electric control signals whose phases are mutually different by 90° and having frequency period with respect to frequency of the output light, a thermal electric cooler on which the wavelength-tunable laser and the frequency locker are mounted, and a controller configured to control temperature of the heaters, and the thermal electric cooler on the basis of any one of the two electric control signals.
Claims13
A wavelength-tunable light source comprising:
- a wavelength-tunable laser including a first region and a second region each of which includes at least one of heaters;
- a frequency locker configured to receive output light of the wavelength-tunable laser and to output two electric control signals whose phases are mutually different by 90°, the two electric control signals having frequency period with respect to frequency of the output light;
- a thermal electric cooler on which the wavelength-tunable laser and the frequency locker are mounted;
- and
- a controller configured to control temperature of the heaters and the thermal electric cooler on a basis of any one of the two electric control signals.
A wavelength control method for a wavelength-tunable light source comprising:
- a wavelength-tunable laser including a first region and a second region each of which includes at least one of heaters;
- a frequency locker configured to receive output light of the wavelength-tunable laser and to output an electric control signal having frequency period with respect to frequency of the output light;
- a thermal electric cooler on which the wavelength-tunable laser and the frequency locker are mounted;
- and
- a controller configured to include a look-up table, the method comprising:
- acquiring a target oscillation frequency;
- selecting a reference frequency closest to the target oscillation frequency from among a plurality of reference frequencies preliminarily stored in the look-up table;
- calculating Δf which is a difference between the target oscillation frequency and the reference frequency;
- calculating temperature TNEW of the thermal electric cooler such that a lock point of the output property of the frequency locker matches to the target oscillation frequency;
- setting and maintaining temperature of the thermal electric cooler to and at the temperature TNEW;
- calculating a first power Pknew as an initial value such that the oscillation frequency of the wavelength-tunable laser matches to the target frequency, where k is a natural number;
- and
- supplying each of the heaters with the first power Pknew.
Dependencies are inferred from the claim text.