ABSTRACT
We present an all-passive efficient KGW Raman laser with an external-cavity configuration in the 2 µm spectral regime. The Raman laser was pumped by a passively Q-switched Tm:YAP laser emitting at 1935 nm. Due to the bi-axial properties of the KGW crystal, the laser exhibits stimulated Raman emission at two separate spectral lines: 2272 nm and 2343 nm. The output energies achieved at these two lines are 340 µJ/pulse and 450 µJ/pulse, accordingly. The seed to Raman laser conversion efficiencies achieved of 19.2% and 23.5%, respectively, are comparable to actively Q-switched laser arrangements. To the best of our knowledge, this is the first time an efficient Raman laser in the 2 µm regime is demonstrated in a completely passive configuration.
ABSTRACT
A pulsed high energy and narrow bandwidth tunable Tm:YLF laser at the milli-Joule level is demonstrated. The spectral bandwidth was narrowed down to 0.15 nm FWHM, while 33 nm of tunability range between 1873 nm and 1906 nm was achieved using a pair of YAG Etalons. The laser was actively Q-switched using an acousto-optic modulator and mJ level pulse energy was measured along the whole tuning range at a repetition rate of 1 kHz. Up to 1.97 mJ of energy per pulse was achieved at a pulse duration of 37 ns at a wavelength of 1879 nm, corresponding to a peak-power of 53.2 kW and at a slope efficiency of 36 %. The combination of both high energy pulsed lasing and spectral tunability, while maintaining narrow bandwidth across the whole tunability range, enhances the laser abilities, which could enable new applications in the sensing, medical and material processing fields.
ABSTRACT
We demonstrated in this paper a watt-level tunable, narrow band, end-pumped Tm:YAP laser. Spectral tunability of 35 nm ranging continuously between 1917-1951 nm with a spectral linewidth of 0.15 nm FWHM was achieved. The tuning and spectral band narrowing were obtained using a pair of YAG etalons. Watt-level output power was measured along the laser tunable range, obtaining a maximal output power of 3.88 W at 1934 nm. A slope efficiency of 44.8% is demonstrated for a maximal absorbed pump power of 12.1 W. The combination of the narrow bandwidth with tunability at those output power levels makes this laser a promising tool for biomedical, sensing, and material processing applications.
