Compact Deep UV System at 222.5 nm Based on Frequency Doubling of GaN Laser Diode Emission

N. Ruhnke, A. Müller, B. Eppich, M. Maiwald, B. Sumpf, G. Erbert, and G. Tränkle

Published in:

IEEE Photonics Technol. Lett., vol. 30, no. 3, pp. 289-292 (2018).

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Laser light sources emitting in the deep ultraviolet wavelength range between 210 and 230 nm are of great interest for spectroscopic applications. Here, a compact DUV diode laser system emitting at a wavelength of 222.5 nm is presented. The system is based on frequency doubling of the laser radiation from a micro-integrated GaN external cavity diode laser module (µECDL) emitting at 445 nm. The µECDL has an optical pump power of 1.4 W with an emission bandwidth of 35 pm. Narrowband laser radiation in continouos wave operation with an output power of 160 µW at 222.5 nm is generated in a single-pass frequency doubling stage with a β-BaB2O4 crystal. The results are suitable to address applications such as spectroscopic investigations of biological samples. The presented concept of a compact and efficient deep ultraviolet laser light source enables the realization of portable systems for which a small footprint and a low power consumption is essential.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany

Index Terms:

Diode lasers, light sources, nonlinear optics, optical harmonic generation, ultraviolet sources.