Abstract

Deep ultraviolet (DUV) lasers are of great interest as excitation light source for Raman spectroscopy. Besides an increase of the Raman cross section with 1/λ⁴ excitation wavelengths below 260 nm could lead to a separation of the Raman signals from fluorescence interference. Single-pass frequency doubling of diode laser emission below 500 nm is a promising concept for realizing a compact laser source with emission wavelengths in the deep UV spectral range. For an efficient frequency conversion pump laser light of several hundreds of milliwatts with narrowband emission is necessary and has not been achieved with diode lasers thus far. Recently, broad-area GaN laser diodes with output powers beyond 1 W in continuous-wave operation have become available, but their broad spectral emission limits their applicability for frequency conversion.

© 2015 IEEE