Wavelength inspection method of a semiconductor laser diode and a wavelength inspection unit thereof
AssigneeFujitsu Quantum Devices Limited
InventorsHaruyoshi Ono, Isao Baba
Life of this patent
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Abstract
In order to tune an oscillation wavelength of a semiconductor laser diode to a target wavelength, the amount of change of a wavelength to the amount of change of a wavelength varying item is determined by actual measurement and a basic wavelength coefficient is renewed by using the ratio of both amounts of change as a corrective wavelength coefficient, and thus the characteristic when the wavelength of an actual device is made closer to a target wavelength is utilized.
Claims16
A wavelength inspection method of a semiconductor laser diode, in which tuning of the semiconductor laser diode using a wavelength varying item for varying a wavelength and a basic wavelength coefficient showing the relation of the amount of change of a wavelength to the change of value of the wavelength varying item is performed, comprising the steps of:
- performing a computation of a first value of the wavelength varying item for obtaining a target wavelength based on the basic wavelength coefficient;
- and performing a computation of a corrective wavelength coefficient by obtaining a measured wavelength of the semiconductor laser diode at the first value of the wavelength varying item, based on the difference between the measured wavelength and the target wavelength.
A wavelength inspection unit of a semiconductor laser diode comprising:
- a laser diode control portion for controlling a value of a wavelength varying item corresponding to the semiconductor laser diode;
- a wavelength measuring portion for measuring a wavelength of the semiconductor laser diode;
- and
- a computer obtaining a difference of wavelengths of the semiconductor laser diode before and after the change of the wavelength varying item given to the semiconductor laser diode from the wavelength measuring portion, performing a computation of a corrective wavelength coefficient by modifying a basic wavelength coefficient based on the amount of change of the wavelength varying item and the difference between a target wavelength and a measured wavelength, performing a computation of a value of the wavelength varying item so that the measured wavelength reaches the target wavelength by using the basic wavelength coefficient or the corrective wavelength coefficient, outputting a value of the wavelength varying item to the laser diode control portion, and inputting data of a temperature and current.
Dependencies are inferred from the claim text.