A Faraday laser locked to 87Rb D2 line.

We present a single-frequency Faraday laser utilizing a 5-Torr-Ar-mixed 85Rb atomic filter as a frequency-selecting element, and lock it to 87Rb D 2 line via modulation transfer spectroscopy (MTS). The wavelength of the free-running Faraday laser fluctuated between 780.2457 and 780.2470 nm, which was limited within the ultra-narrow transmission bandwidth (700 MHz) of the atomic filter. When the Faraday laser was stabilized to 87Rb 52S 1/2 F = 2 → 52P 3/2 F′ = 3 hyperfine transition line, the output wavelength of the laser was approximately 780.24602 nm, and the fractional frequency Allan deviation measured by residual error signal arrived at 2.87 × 10−14 at 1 s, then reached 1.25 × 10−14 at 100 s. The laser system is easy to be locked to 87Rb D 2 line within the current range of laser diode (LD) from 75 to 140 mA, which has the potential to achieve a "turnkey" systems and is suitable for laser-pumped rubidium atomic clocks and laser-cooling experiments. • A single frequency Faraday laser locked to 87Rb 87Rb 52S 1/2 F = 2. → 52P 3/2 F′ = 3 hyperfine transition line is reported, for the best to our knowledge. • A85Rb atomic filter mixed with 5-Torr buffer gas Ar is investigated experimentally for the first time. • The wavelength of the free-running Faraday laser is corresponded to the 87Rb Doppler resonance absorption line. • The fractional frequency Allan deviation of frequency stability in frequency-locking operation is at 2.87 × 10−14 at 1 s by estimation of residual error signal. [ABSTRACT FROM AUTHOR]