Laser to microwave frequency division using synchrotron radiation II

We present a review of theoretical calculations which demonstrate the feasiblity of obtaining one step frequency division from optical or infrared laser frequencies to a subharmonic in the microwave spectral region, and include current experimental designs toward a practical realization of this goal. We plan to drive the cyclotron orbit of a single relativistic electron, which is confined in a Penning ion trap, with a laser beam focused to a spot diameter ~λ. This method is an extension of a common technique used in cyclotrons and synchrotrons where the orbit of high energy particles is driven at a harmonic of the orbit frequency. Our experiment is designed to measure this orbit frequency which is then a subharmonic of the driving (laser) frequency. This technique requires that the uncertainty in the electron orbit dimensions be limited to ⩽ λ/2, which is possible by radiative cooling and the method of motional sideband excitation. The possibility of a unified optical wavelength/frequency standard is evident.