Light source control method

摘要

The present invention relates to a light source control method capable of decreasing the dependence of a pulse width (FWHM) of an output pulsed light on a repetition frequency. A pulsed light source has an MOPA structure, and has a seed light source and an optical fiber amplifier. The seed light source includes a semiconductor laser which is directly modulated and outputs a pulsed light. By adjusting a temperature of the seed light source and a pumping light power of the optical fiber amplifier, a predetermined full width half maximum of a pulse at a predetermined repetition frequency is implemented for the pulsed light outputted from the optical fiber amplifier.

主权项

1. A light source control method, comprising steps of:
preparing a pulsed light source which comprises: a semiconductor laser that is directly modulated and outputs pulsed light in a predetermined repetition frequency; an optical filter that inputs the pulsed light outputted from the semiconductor laser and outputs shaped-pulsed light in which one side between either a shorter wavelength side and a longer wavelength side of a wavelength band of the input pulsed light is more attenuated than the other side, the shorter wavelength side and the longer wavelength side being separated at a peak wavelength of the input pulsed light; and an optical fiber amplifier that amplifies the shaped-pulsed light outputted from the optical filter and outputs the amplified-pulsed light, the optical fiber amplifier including a pumping light source that is different from the semiconductor laser and outputs pumping light for amplifying the shaped-pulsed light; and widening or narrowing a full width half maximum of pulse in the amplified-pulsed light to be outputted from the optical fiber amplifier in the predetermined repetition frequency, by adjusting a temperature of the semiconductor laser and a pumping light power of pumping light source to implement a target full width half maximum of pulse.