Femtosecond optical frequency comb laser based on cesium 6s–8s 822 nm hyperfine transition

We construct a highly stable comb laser based on one compact 822 nm diode laser and one 25-mm long cesium vapor cell, for the first time to our knowledge. It is advantaged that more than 99% comb laser power could be delivered to user since no any nonlinear process is needed for locking laser frequency. The relative merits of atomic transition- based frequency combs are discussed and we demonstrated a novel way on controlling and scanning the carrier-envelop offset frequency by shifting slightly the pump beam.