Study on dual wavelength powder frequency doubling detection system

In order to measure the frequency doubling characteristics of powder materials, according to the theory of Kurtz-Perry powder frequency doubling effect and the theory of optical parametric oscillation, dual wavelength Q-switched laser output of 130mJ@1064nm and 20mJ@1570nm was obtained. After theoretical analysis and experimental verification, the 1064nm and 1570nm dual wavelength frequency doubling test of powder sample was realized. The problem, that the absorption of crystal powder material to the wavelength of frequency doubling signal makes it difficult to measure the frequency doubling signal when testing the single wavelength, was solved. The results show that the test sensitivity of effective nonlinear coefficient reaches 0.46pm/V. the variation trend of frequency doubling signal of KTP powder samples is consistent with the theory. The system is stable, simple, convenient and reliable for nonlinear detection of crystals.