Abstract
We construct a frequency stabilized extended-cavity diode laser (ECDL) at 822.5nm wavelength that could be a reliable frequency reference. The laser frequency is locked to the Cs 6S 1/2 →8S 1/2 two-photon-transition (TPT) with the Allan deviation of 4.4×10 -13 (60 s). The possible systematic error is evaluated as 2 kHz. [1] ©2008 IEEE.