Frequency locking of multiple lasers to an optical cavity

We demonstrate the locking of multiple lasers to an ultralow expansion cavity using a single fiber electro-optical modulator. We use this modulator to lock the frequency of one of the sidebands to the cavity resonance using an extension of the Pound-Drever-Hall technique. The frequency of the carrier can be tuned by changing the sidebands' separation. We distinguish the signal coming from different lasers by their modulation frequency in the demodulation. The scheme is scalable to a large number of lasers without requiring extra optical components. (C) 2018 Optical Society of America