Optical sampling ADC based on dual optical frequency combs with rubidium frequency reference

This paper reports an optical sampling analog-to-digital converter (ADC) system based on dual optical frequency combs with a rubidium (Rb) coherent population trapping (CPT) atomic resonator. The repetition frequency of one mode-locked laser (MLL) is locked to an
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Rb 3.035 GHz CPT atomic resonance. The repetition frequency of the other MLL is locked to the Rb frequency reference with a little difference. The optical pulses trains of these two lasers are coupled to implement highspeed optical sampling ADC system. This scheme provides a portable and long-term stable approach for optical sampling ADC system based on dual optical combs.