Frequency Difference Thermally And Electrically Tunable Dual-Frequency Nd:Yag/Litao3 Microchip Laser

This study presents a dual-frequency microchip laser with a thermo-optically and electro-optically tuned frequency difference. The dual-frequency microchip cavity is formed by bonding a Lithium tantalite (LiTaO3, LTO) crystal chip and a neodymium-doped yttrium aluminum garnet (Nd:YAG) crystal chip. A single longitudinal mode is generated by the Nd:YAG crystal and split into two frequencies with perpendicular polarizations due to birefringent effect in the LTO chip. Furthermore, continuous beat frequency tuning at different scales is realized by adjusting the temperature and voltage applied to the LTO crystal. A maximum beat frequency of up to 27 GHz is obtained, and the frequency difference lock-in phenomenon is observed below the frequency difference of 405 MHz.