Frequency locking of a 1324 nm DFB laser to an optically pumped rubidium vapor

Some experimental results and a simple theoretical model on a dither-free frequency-locking technique of a DFB laser operating at 1324 nm are presented. A resonance observed through absorption in an ⁸⁷ Rb vapor optically pumped by a modulated 795-nm laser diode tuned to the D₁ line is used. This approach has the advantage of producing sub-Doppler resonances. Such a technique could be used to generate an unmodulated 1324-nm wavelength reference