Widely tunable ultraviolet C generation using wavelength selectiveexternal high-Q-cavity and a blue laser diode system

摘要

This paper presents a second harmonic generation scheme using a nonlinear optic crystal and a multimode Fabry-Perotblue laser diode that has potential to generate widely tunable coherent deep ultraviolet at approximately 225 nm. Usingthe Fabry-Perot multimode laser diode with the sum-frequency technique, a high second harmonic power is hardlyobserved due to low conversion efficiency. In this paper, an approximately 1 μW second harmonic ultraviolet power ataround 225 nm ultraviolet wavelength and approximately 6 nm ultraviolet wavelength tunability can be obtained using amulti mode blue LD chip, a nonlinear optic crystal, and an external high-Q-cavity setup.