US 2010/0150189 A1 · LASER CONTROL METHOD AND LASER CONTROL CIRCUIT

Abstract

A laser control method includes the steps of: using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output; calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier; inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively; and controlling the applied laser output from the semiconductor laser element by performing calibration.

Claims15

Dependent claims

A laser control method comprising the steps of:

using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output;
calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier;
inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively;
and
controlling the applied laser output from the semiconductor laser element by performing calibration.

2 more elements

A laser control circuit comprising:

a constant current circuit configured to maintain a constant current flowing through a semiconductor laser element;
an adder connected to an operational amplifier of the constant current circuit, and configured to receive an input of a reference bias value calculated on the basis of a detection signal output from detection means for detecting an applied laser output from the semiconductor laser element;
and
a multiplier connected to the adder, and configured to receive an input of an input signal and an input of a reference gain value calculated on the basis of a detection signal output from the detection means,
wherein the applied laser output from the semiconductor laser element is automatically controlled.

2 more elements

Dependencies are inferred from the claim text.

Laser control method and laser control circuit

Life of this patent

Laser control method and laser control circuit

Life of this patent

Abstract

Claims15