Nd:YLF/KGW intracavity Raman laser in DBMC configuration at 1147 and 1163 nm in TEM00

Abstract

A Nd:YLF / KGW intracavity Raman laser in DBMC (double-beam-mode-controlling) configuration has been investigated in this work. The fundamental wavelength laser was generated using a Nd:YLF crystal pumped in DBMC configuration generating an emission wavelength of 1053 nm in σ-polarization. A VBG (volume-Bragg-grating) equipped diode emitting at 797 nm was used as pump source. The KGW crystal has two strong Raman lines, 768 cm-1 and 901 cm-1, generating two Raman wavelengths at 1147 nm and 1163 nm, respectively. The DBMC technique allows to produce TEM00 stable output in a side-pumped configuration with no requirement to introduce any additional mode selection technique, thus achieving high efficiency for fundamental TEM00 operation. The high power density of the fundamental laser combined with intracavity Stokes conversion produces an efficient Raman laser. Allying both techniques, the Nd:YLF in DBMC configuration and the intracavity Raman generation, it was possible to generate an output power at 1163 nm of 3.2 W corresponding to a diode-to-Raman conversion efficiency of 8% with slope efficiency of 8.8 %. For the emission at 1147 nm, 3.5 W of output power was achieved with a diode-to-Raman conversion efficiency of 11% and slope efficiency of 9%. The beam quality was M2 =1.9 and 1.1 in the horizontal and vertical direction, respectively. This is, to our knowledge, the first report of a side-pumped Nd:YLF/KGW intracavity Raman laser in DBMC configuration.