Generation of 14  W at 589  nm by frequency doubling of high-power CW linearly polarized Raman fiber laser radiation in MgO:sPPLT crystal

Abstract

We introduce an efficient, single-mode, linearly polarized continuous wave (CW) Raman fiber laser (RFL), operating at 1178 nm, with 65 W maximum output power and a narrow linewidth of 0.1 nm. Single-pass second-harmonic generation was demonstrated using a 20 mm long MgO-doped stoichiometric periodically polled lithium tantalate (MgO:sPPLT) crystal pumped by RFL radiation. Output power of 14 W at 589 nm with 22% conversion efficiency was achieved. The possibility of further power scaling is considered, as no crystal degradation was observed at these power levels.

Investigation on extreme frequency shift in silica fiber-based high-power Raman fiber laser

“…Therefore, RFL has been explored to achieve high-power output at specialized wavelengths [2][3][4][5][6][7][8][9][10] , which are rather challenging for lasing or amplifying efficiently by rare earthdoped fibers [11][12][13] . To date, high-power RFLs have been widely investigated and applied in optical pumping, frequency conversion, optical communications, biology and scientific research [14][15][16][17][18][19][20][21][22] . It is well known that the Raman gain in silica fibers extends over a large frequency range up to 40 THz [23] .…”

Investigation on the thermal characteristic of MgO:PPSLT crystal by transmission spectrum of a swept cavity

“…However, the second harmonic (SH) wavelength of 400 nm is close to the transmission window edge of KTP, the severe absorption of the generated UV laser and the intrinsic gray tracking limit the output power of the generated UV laser and shorten the lifetime of the crystal. Recently, a new nonlinear crystal MgO:PPSLT is attached to importance owing to its intrinsic advantages including high thermal conductivity, high photo-refractive damage as well as broad transmission wavelength range and has been successfully used to generate green and yellow lasers [6][7][8][9]. Some groups also used MgO:PPSLT crystals to generate UV laser, but the powers were all at low level [10,11].…”

Generation of high-power single-frequency 3975 nm laser with long lifetime and perfect beam quality in an external enhancement-cavity with MgO-doped PPSLT

“…However, the photo-refractive effect of BIBO crystal limited the frequency doubling process and the intrinsic walk-off effect of the angular phase-matched BIBO and LBO crystals badly influenced the output beam quality. Recently, a novel periodically poled Mg-doped stoichiometric lithium tantalate (MgO:PPSLT) crystal has drawn greater attention owing to its high effective nonlinear coefficient, high thermal conductivity, high photo-refractive damage as well as broad transmission wavelength range and has been successfully used to obtain the stable single-frequency 532 nm and 589 nm laser [10][11][12][13][14]. In 2009, Ricciardi et al realized a 7 mW 355 nm laser in PPSLT crystal [15].…”