A method for measuring optical frequencies from the UV to the near IR relative to a microwave frequency standard is proposed. The concept is to measure the frequency difference of two known ratios (½ and ⅔) of an optical frequency ƒ relative to the cesium clock. By employing optical parametric oscillators and wideband modulators to link the (½)ƒ and (⅔)ƒ frequencies, a precise and accurate optical frequency comb can be provided in the ~1–2-µm wavelength region. By using this comb, most optical frequencies from the UV to the near IR can be measured or synthesized. A configuration for measuring the frequency of the hydrogen 1S-2S transition is described.
© 1992 Optical Society of America
N. C. Wong, "Optical frequency counting from the UV to the near IR," Opt. Lett. 17, 1155-1157 (1992)