Intensity-modulated blue light generated by frequency doubling of wavelength-modulated high-power diode-laser radiation

Abstract

A scheme for the generation of modulated blue laser radiation is demonstrated. The 923nm radiation of a high-power diode-laser master-oscillator power-amplifier system is wavelength modulated within a range of 0.2nm by modulating the injection current of the distributed feedback (DFB) diode oscillator. Single-pass frequency doubling of the generated radiation in periodically poled potassium titanyl phospate converts the wavelength modulation into an intensity modulation with a contrast ratio exceeding 700:1. The 3dB modulation bandwidth of 35kHz is limited by the speed of the wavelength tuning of the DFB oscillator.