The iodine molecule has frequently been used as a frequency reference from the green to the near-infrared wavelength region (500-900 nm). We describe the frequency locking of the second-harmonic signal of a 197.2-THz (1520.25-nm) distributed-feedback diode laser to the absorption lines of the iodine hyperfine structure; a frequency jitter below 0.1 MHz was achieved at a 300-ms time constant. This scheme provides a simple, compact, and high-performance frequency reference in the optical communication band.
© 2005 Optical Society of America
Hsiang-Chen Chui, Sen-Yen Shaw, Ming-Sheng Ko, Yi-Wei Liu, Jow-Tsong Shy, Tyson Lin, Wang-Yau Cheng, Rostislav V. Roussev, and Martin. M. Fejer, "Iodine stabilization of a diode laser in the optical communication band," Opt. Lett. 30, 646-648 (2005)