1560nm CW Frequency Doubling And Frequency Locking Via Rubidium Absorption Spectroscopy

It is well-known that 780nm is corresponding to the transition wave-length of the D2 line of Rubidium (Rb) atom. It is played an important role in scientific research, especially in cold atoms, quantum optics and so on. Now 780nm laser diode is commercially, but we can't directly obtain a pulse laser with higher peak power, pulse width and repetition rate can modulatable and frequency stability.The second harmonic of optical communication wavelength 1560nm is 780nm. A continuously wave 1560nm from a diode laser sliced into pulse laser, and injected into Er-doped fiber amplifier (EDFA) achieved Watts level laser source. The higher laser source single-pass quasi phase match (QPM) crystal and obtain a stable 780nm pulse laser. The main works of this dissertation are as follows:(1) We introduced the background of the experiment system and the theory of second harmonic generation, and then we discussed the important factor phase matching. In this paper, we mainly introduced a new phase matching technique-QPM.(2) The characteristics of PPLN crystal. We selected a multiple period PPLN crystal in our experiment. We obtained～25.2mW 780nm laser when the 1.37W 1560nm laser Injected into the crystal and the SHG efficiency is 1.75% and nonlinear conversion efficiency 1.27%/W.(3) The characteristics of PPKTP crystal. We selected a single period PPKTP crystal in our experiment. We obtained～15mW 780nm laser when the input power of 1560nm is 1.37W and the SHG efficiency is 1.09% and nonlinear conversion efficiency 0.84%/W(4) We seeded the 1560nm DFB laser into EDFA and amplified for frequency doubling by using PPLN crystal, and then we stabilized the 1560 nm DFB laser on Rb absorption spectroscopy. The laser frequency drift is 52 MHz in free running and the residual frequency fluctuation is～±3.5 MHz in 30 s.