Method to control emission wavelength of tunable laser diode
AssigneeSumitomo Electric Industries, Ltd.
InventorsTomoko IKAGAWA, Keiji TANAKA
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Abstract
A method to control the emission wavelength of a tunable laser diode (LD) is disclosed. The method measures the first derivative of the wavelength against the first stimulus, typically a current injected in the SG-DFB region, and the second derivative of the wavelength against the power supplied to the heater in the CSG-DBR region. The method adjusts the current so as to coincide the emission wavelength with the target wavelength, then, corrects the target power for the heater based on the derivative of the current multiplied by a ratio of two derivatives measured in advance to the control of the heater current.
Claims14
A method to control an emission wavelength of a tunable LD that provides a first region attributed to tune the emission wavelength by a first stimulus and a second region attributed to tune the emission wavelength by a second stimulus, comprising steps of:
- calculating a first derivative of the emission wavelength against the first stimulus supplied to the first region and a second derivative of the emission wavelength against the second stimulus supplied to the second region;
- adjusting the first stimulus by a first deviation to coincide the emission wavelength with a target wavelength;
- adjusting a target stimulus for the second stimulus based on the first deviation of the first stimulus, the first derivative and the second derivative;
- and
- adjusting the second stimulus by a second deviation to coincide with the second stimulus with the target stimulus.
Dependencies are inferred from the claim text.