A Passively Wavelength-Stabilized Mid-Infrared Optical Parametric Oscillator
Liemao Hu,
Yunze He,
Xinjie Lv,
Jian Ning,
Gang Zhao,
Shining Zhu
Affiliations
Liemao Hu
National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Science, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
Yunze He
National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Science, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
Xinjie Lv
National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Science, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
Jian Ning
National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Science, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
Gang Zhao
National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Science, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
Shining Zhu
National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Science, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
High-power and widely tunable continuous-wave optical parametric oscillators (cw OPOs), as mature radiation sources in the mid-infrared range, are limited by their frequency fluctuation. We built a cw OPO working at the near- and mid-infrared ranges and discuss the extent to which its frequency stability is affected by the mechanical temperature and the air pressure of the cavity. In addition, we artificially provoked mode hops by changing the above two factors to analyze the thermal-induced refractive index variation of the crystal. An inequality between the spacing of the hops and the free spectrum range (FSR) was observed. The wavelength stability of the cw OPO was guaranteed passively, and the longest mode-hopping-free time exceeded 13 h through sealing the cavity and thermal control. Further analysis of factors affecting frequency drift is critically essential for the reliability of cw OPO, particularly in environments outside the laboratory, and may provide a new method for high-precision tuning wavelengths.
