Optical atomic clocks have reached unprecedented accuracy and precision and have the potential to revolutionize metrology. However, many of the applications of optical clocks, such as detection of dark matter and gravitational waves, deep space navigation, measurements of variations in fundamental constants, and precision geodetic measurements,require compact portable clocks. Building optical atomic clocks on a scale suitable for most field applications is an ongoing challenge in the precision metrology community.

This seminar describes a clock that can be made smaller and simpler than most existing optical clocks, while still operating with state-of-the-art precision. The basis for these improvements is using a two-photon transition which eliminates the need for sub-Doppler cooling and tight confinement of the atoms. An overview of optical atomic clocks will be given and details of the two-photon calcium clock will be described along with recent experimental results. The work described in this seminar represents an advancement in the development of compact portable optical clocks which will further push the boundaries of precision measurement and our understanding of the universe.