Patent ID: 11923659
Assignee: FURUKAWA ELECTRIC CO., LTD.
Field: Optics (Instruments)
Classification: CPC H | IPC H

Claim 2:
3. A method for calibrating an optical module, the optical module including:
a laser light source unit configured to emit a laser beam;
a wavelength filter having a periodical transmission characteristic with respect to a wavelength of light;
a temperature controller on which the wavelength filter is placed and that is configured to adjust a temperature of the wavelength filter;
a heat generating body placed on the temperature controller;
a first light receiving element configured to receive the laser beam which has not been transmitted through the wavelength filter, and output a current value based on an intensity of the received laser beam;
a second light receiving element configured to receive the laser beam which has been transmitted through the wavelength filter, and output a current value based on an intensity of the received laser beam; and
a control device configured to control the wavelength of the laser beam emitted from the laser light source unit and control the transmission characteristic of the wavelength filter based on an intensity of the laser beam transmitted through the wavelength filter,
the method comprising:
fitting by performing wavelength calibration at a plurality of current values of the heat generating body, and performing fitting on at least one of
a difference between
a current ratio between the current value output from the first light receiving element and the current value output from the second light receiving element at a reference current value among the current values, and
a current ratio between the current value output from the first light receiving element and the current value output from the second light receiving element at a current value other than the reference current value among the current values, and

a difference between
a wavelength filter temperature of the wavelength filter at the reference current value among the current values, and
a wavelength filter temperature of the wavelength filter at a current value other than the reference current value among the current values; and

recording a coefficient obtained by the fitting into a memory.