Generation of 15  W average power, 18  kHz repetition rate coherent mid-ultraviolet radiation at 2712  nm

Abstract

This paper presents to our knowledge a first time study on the generation of 1.5 W average power, 18 kHz repetition rate coherent mid-ultraviolet (UV) radiation at 271.2 nm. The work is based on frequency summing of coherent green (G: 510.6 nm) and yellow (Y: 578.2 nm) radiations of a copper-HBr laser in a β-barium borate crystal. Average and peak sum frequency conversion efficiencies of about 13% and 16%, respectively, are obtained. The sum frequency results are experimentally analyzed in terms of the extent of matching of green and yellow pump radiations in space, time, and frequency domains. The result is of high significance for many applications in photonics components fabrication, semiconductor technology, and spectroscopy.

Non-degrading CW UV generation in β-barium borate at 257 nm using an elliptical focusing enhancement cavity

“…However, no long-term measurements were presented. Elliptical focusing schemes have also been used for non-linear conversion processes with pulsed copper vapour lasers [3][4][5]. Steinbach et al gave a mathematical expression for the conversion efficiency of SHG under walk-off and elliptical focusing [16].…”

High-energy, hundred-picosecond pulsed 266 nm mid-ultraviolet generation by a barium borate crystal

“…Mid-ultraviolet (mid-UV, λ = 250–300 nm) radiation [ 1 ] with high photon energy, high pulse energy, high peak power and short pulse duration has attracted a great deal of attention in micromachining [ 2 ] , fluorescence research [ 3 ] , spectral analysis [ 4 – 6 ] and other applications. Compared with traditional excimer lasers [ 7 ] , all-solid-state mid-UV lasers based on frequency conversion [ 8 ] have many advantages in applications, such as compactness, high efficiency, long lifetime, high stability and low cost of system maintenance [ 9 ] .…”