Temporally and spatially shaped fully-fiberized ytterbium-doped pulsed MOPA

Abstract

We report a fully-fiberized, pulsed ytterbium-doped master oscillator power amplifier (MOPA) for materials processing applications providing both a temporal pulse and spatial beam shaping capability operating at a maximum average output power of 100 W. Adaptive temporal pulse shaping using an in-line electro-optic modulator was incorporated to reduce the impact of dynamic gain saturation and optical Kerr/Raman nonlinearities. The MOPA is capable of generating 2.5 mJ flat-topped optical pulses with 20 kW peak power as well as other user-defined, shaped pulses. Spatial beam shaping is obtained using a pair of axicon (conical) lenses at the end of the beam delivery optic allowing ring shaped output beams to be generated from the otherwise collimated Gaussian output.

Large aperture PPMgLN based high-power optical parametric oscillator at 38 µm pumped by a nanosecond linearly polarized fiber MOPA

“…Moreover, we designed and fabricated a larger aperture PPMgLN wafer which allows for a relatively large focused beam waist which helps to reduce thermal-lens effects. Using adaptive pulse shaping of the seed diode [12,13] we demonstrate a reduction in the impact of dynamic gain saturation and optical Kerr/Raman nonlinearities [14] within the fiber MOPA, obtaining shaped signal and idler pulses at the OPO output. A total OPO power output of 21 W with an idler power of 5.5 W at 3.8 µm were obtained at a pump power of 58 W, with no sign of thermal roll-off indicating considerable scope for further power scaling.…”

Spectroscopic properties of Yb-doped CaF2–YF3solid-solution laser crystal

“…Recently, lasers are being developed at an increasing pace, including continuous and pulsed lasers [1][2][3][4][5][6][7]. Ytterbiumdoped alkaline-earth fluorides (Yb:CaF 2 , Yb:SrF 2 , Yb:BaF 2 ) have attracted considerable interest for use in diode-pumped, femtosecond lasers and amplifiers [8][9][10][11].…”

A sub-nanosecond narrow-linewidth pulsed laser source with controllable repetition rate

“…Pulsed fiber lasers and amplifiers have attracted much attention for applications that require short pulses at a multi-kHz pulse repetition rate (PRR) and excellent signal-to-noise ratio, exhibiting one or more of the following characteristics: high peak power [1][2][3][4], high pulse energy [5][6][7], and narrowlinewidth spectrum [8][9][10]. These fiber lasers, principally by virtue of their remarkable advantages of excellent beam quality, high reliability, compactness and heat dissipation, are extensively applied in scientific research, industrial production and national defense, for operations such as harmonic generation, materials processing, remote sensing, ranging and imaging [11][12][13][14].…”