To meet the light source requirement for image positioning of the lightning imager on board the Fengyun-4 meteorological satellite,a laser with a central wavelength of 777.4 nm and a continuous output power of 1.5 W is designed based on a two-stage master oscillation power amplifier structure(MOPA)and a periodically polarized lithi-um niobate crystal doped with magnesium oxide(MgO:PPLN)to double the frequency.Using 940 nm off-peak pum-ping technology to suppress the amplified spontaneous emission(ASE)and stimulated Brillouin scattering(SBS)in the optical amplifier,we obtain a single-frequency narrow linewidth laser with an output power of 15 W,a signal-to-noise ratio of 59.6 dB,a linewidth of 323.4 kHz,and a relative intensity noise of-145 dBc/Hz.The optical-optical conversion efficiency of the amplifier is up to 37.2％.Based on the theoretical analysis of the doubling efficiency,tem-perature-tuned bandwidth,and acceptable wavelength bandwidth of the MgO:PPLN crystal used,777.4 nm continu-ous light with a power of 1.5 W is obtained using a single-pass doubling method.
关键词
非线性晶体倍频/准相位匹配/光纤放大器/放大自发辐射/受激布里渊散射
Key words
nonlinear crystal frequency doubling/quasi-phase-matching/fiber amplifier/amplifier spontaneous emission/stimulated Brillouin scattering
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