Recently, the research team led by Zhang Tianshu, a researcher at the Anhui Institute of Optics and Mechanics of the Chinese Academy of Sciences in Hefei, has made new progress in the research of all-solid-state continuous single-frequency laser technology. The relevant findings have been published in the internationally renowned optical field journal Optics and Laser Technology.
The team utilized a four-mirror ring cavity with a single-ended LD pumped Nd:YVO₄ (neodymium-doped yttrium vanadate) crystal to generate 1064-nanometer continuous single-frequency laser output. By combining iodine molecular frequency locking technology, they achieved precise control over the output laser frequency. These research findings are expected to serve as core components for environmental monitoring instruments and equipment, such as those used for atmospheric pollution and greenhouse gas detection, thereby providing robust support for atmospheric environmental protection and climate change research.
The single-frequency characteristics of the laser make it an ideal core component for environmental monitoring instruments, enabling applications such as the detection of atmospheric volatile organic compounds, atmospheric wind fields, and near-space environments. Continuous single-frequency lasers are also widely used in fields such as laser amplifiers, gravitational wave detection, and quantum optics. Advances in single-frequency laser technology have significantly promoted the development of atmospheric remote sensing. These applications not only require the laser to emit a single frequency but also demand strict stability in the laser frequency. However, existing semiconductor lasers and fiber lasers have limitations in environmental adaptability and struggle to meet the demands of high-performance applications.
Figure 1 Schematic diagram of a fully solid-state single-frequency continuous 1064 nm laser
Figure 2 Laser linewidth characteristics and frequency stability under locked control
Figure 3 Physical diagram of the laser system's appearance and internal layout
The research team adopted a ring resonator cavity structure combined with iodine molecular absorption frequency locking technology to achieve long-term frequency stability for single-frequency lasers. This technology locks the laser frequency to the side wings of the iodine molecule's specific absorption spectrum and uses feedback control to adjust the resonator cavity length, thereby achieving high-precision frequency stability. The results show that the laser output beam quality is excellent, with M2 factors of 1.05 (horizontal direction) and 1.19 (vertical direction), indicating good spatial distribution characteristics; the output laser linewidth is less than 10 megahertz, demonstrating good single-frequency characteristics; In free-running mode, the laser frequency drift exceeds 200 megahertz within a certain time period. However, in locked mode, the laser maintains frequency stability within ±4 megahertz after continuous operation for 7 hours, significantly improving frequency stability. Additionally, to meet future requirements for device integration, such as laser miniaturization and stability, the engineering design and system integration of a continuous single-frequency laser based on opto-mechanical-thermal coupling have been realized.
