Nonlinear Optics|2 Article(s)
Effect of Temperature on the Output Angle and Conversion Efficiency of Parametric Down Conversion
Yuan-dong QIAN, Mao-peng XIA, Jian-jun LI, Wen-chao ZHAI, and Ming-ming XU
The effect of temperature change of BBO nonlinear crystal on the photon output angle and conversion efficiency of spontaneous parametric down-conversion is studied, so as to obtain the appropriate operating temperature of BBO nonlinear crystal and reduce the influence of temperature on the long-term stability of the system. The crystal clamping and temperature control system is designed according to the experimental requirements, and the feasibility and reliability of the system are guaranteed by ANSYS thermal analysis. After that, by changing the crystal heating temperature, the relevant photon output angle and the change curve of photon number rate with temperature under different beam masses were measured under the temperature control accuracy of no less than ±0.03℃. The results show that with the increase of crystal temperature, the output angle of relevant photon decreases proportionally with the change of temperature, which is consistent with the theoretical calculation results. Meanwhile, the increase of BBO crystal temperature from 25℃ to 55℃ can increase the photon rate of poor beam quality by about 34%, and the subsequent temperature increase in a small range will greatly increase the background noise of measurement while increasing the photon rate. Based on the comprehensive results, it can be seen that the temperature used by BBO crystal in the working process should be 55℃.
Acta Photonica Sinica
  • Publication Date: Oct. 15, 2020
  • Vol. 49, Issue 10, 1019001 (2020)
Generation and Modulation of Rogue Waves on Periodic Background
Shu-qing LI, Yong-xi CHENG, and Feng CHANG
In order to study the excitation and evolution of rogue waves in the periodic background, the excitation and evolution of rogue waves in the case of two kinds of periodic potentials (real potential and complex potential) are discussed by using the split-step fast Fourier transform, according to the self-focusing nonlinear Schrodinger equation model with periodic external potential. The results show that rogue waves can be excited by plane waves with a little perturbation in both kinds of periodic potential backgrounds. In the case of only real periodic potential, different optical phenomena can be generated by changing the amplitude and period of the period potential. In the parity-time symmetry periodic potential, a very large rogue wave can be excited, and the real part amplitude has energy dissipation and deceleration effect on the rogue wave, while the imaginary part amplitude has energy gain and acceleration effect on the rogue wave. Therefore, choosing appropriate real part amplitude and imaginary part amplitude can generate large rogue wave with different intensity. The study can help to capture and adjust the strange wave in the optical lattice, and get high power waves.
Acta Photonica Sinica
  • Publication Date: Jun. 25, 2020
  • Vol. 49, Issue 6, 0619001 (2020)