Difference-frequency combs in cold atom physics

Abstract

Optical frequency combs provide the clockwork to relate optical frequencies to radio frequencies. Hence, combs allow to measure optical frequencies with respect to a radio frequency where the accuracy is limited only by the reference signal. In order to provide a stable link between the radio and optical frequencies, the two parameters of the frequency comb must be fixed: the carrier envelope offset frequency $f_{\mathrm{ceo}}$ and the pulse repetition-rate $f_{\mathrm{rep}}$. We have developed the first optical frequency comb based on difference frequency generation (DFG) that eliminates $f_{\mathrm{ceo}}$ by design - specifically tailored for applications in cold atom physics. An $f_{\mathrm{ceo}}$-free spectrum at 1550 nm is generated from a super continuum spanning more than an optical octave. Established amplification and frequency conversion techniques based on reliable telecom fiber technology allow generation of multiple wavelength outputs. In this paper we discuss the frequency comb design, characterization, and optical frequency measurement of Sr Rydberg states. The DFG technique allows for a compact and robust, passively $f_{\mathrm{ceo}}$ stable frequency comb significantly improving reliability in practical applications.

Cited by in corpus (4)

• Rydberg Electrometry for Optical Lattice Clocks
• Measurement of the strontium triplet Rydberg series by depletion spectroscopy of ultracold atoms
• Absolute Frequency Atlas from 915 nm to 985 nm based on Laser Absorption Spectroscopy of Iodine
• Characterization of Long-Term Stable Photonic Microwaves based on a Difference Frequency Comb