Patent ID: 7653101
Filing Date: 2010-01-26
Classification: H01S

Abstract:
1. A method for operating a semiconductor laser light emitting system, comprising: emitting a laser light by modulating a current supplied to a semiconductor laser device; detecting the laser light and generating a detected voltage in accordance with an intensity of the laser light; supplying the current from a voltage/current conversion device to the semiconductor laser device; storing electric charge in a sample/hold device and outputting a voltage to the voltage/current conversion device; outputting a first current charging the sample/hold device until the detected voltage is equivalent to a first reference voltage; and charging the sample/hold device with a second current while comparing the detected voltage with a second reference voltage less than the first reference voltage when the semiconductor laser device is turned on; wherein charging terminates when the detected voltage is equal to or more than the second reference voltage, and wherein said sample/hold device stores only the first current charge after the charging terminates.