Digital Processing of RF Signals from Optical Frequency Combs
The presented work is focused on digital processing of beat note signals from a femtosecond optical frequency comb.The levels of mixing products of single spectral components of the comb with CW laser sources are usually very low compared to products of mixing all the comb components together.RF counters are more likely to measure the frequency of the strongest spectral component rather than a weak beat note.Proposed experimental digital signal processing system solves this problem by analyzing the whole spectrum of the output RF signal and using software defined radio (SDR) algorithms.Our efforts concentrate in two main areas: Firstly,using digital servo-loop techniques for locking free running continuous laser sources on single components of the fs comb spectrum.Secondly,we are experimenting with digital signal processing of the RF beat note spectrum produced by f–2f 1 technique used for assessing the offset and repetition frequencies of the comb,resulting in digital servo-loop stabilization of the fs comb.Software capable of computing and analyzing the beat-note RF spectrums using FFT and peak detection was developed.A SDR algorithm performing phase demodulation on the f– 2f signal is used as a regulation error signal source for a digital phase-locked loop stabilizing the offset frequency of the fs comb.
femtosecond laser comb stabilization SDR FFT digital signal processing
Martin Cizek Radek Smid Zdenek Buchta Bretislav Mikel Josef Lazar Ondrej Cip
Department of coherence optics, Institute of Scientific Instruments of the Academy of Sciences of the Czech Republic, Brno, Czech Republic
国际会议
2012第八届精密工程测量和仪器仪表国际研讨会(ISPEMI2012)
成都
英文
1-5
2012-08-08（万方平台首次上网日期，不代表论文的发表时间）