Remotely manageable system for stabilizing femtosecond lasers

0437909 - ÚPT 2015 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Čížek, Martin - Hucl, Václav - Šmíd, Radek - Mikel, Břetislav - Lazar, Josef - Číp, Ondřej
Remotely manageable system for stabilizing femtosecond lasers.
Laser Sources and Applications II (Proceedenigs of SPIE 9135). Bellingham: SPIE, 2014, 913527:1-6. ISBN 9781628410839. ISSN 0277-786X.
[Laser Sources and Applications /2./. Brussels (BE), 14.04.2014-17.04.2014]
Grant CEP: GA ČR GAP102/10/1813; GA MŠMT ED3.1.00/12.0232; GA MŠMT(CZ) LO1212
Institucionální podpora: RVO:68081731
Klíčová slova: femtosecond lasers * lasers * signal processing * frequency combs * laser spectroscopy * clocks * digital signal processing
Kód oboru RIV: BH - Optika, masery a lasery

In the field of precise measurement of optical frequencies, laser spectroscopy and interferometric distance surveying the optical frequency synthesizers (femtosecond combs) are used as optical frequency references. They generate thousands of narrow-linewidth coherent optical frequencies at the same time. The spacing of generated components equals to the repetition frequency of femtosecond pulses of the laser. The position of the comb spectrum has a frequency offset that is derived from carrier to envelope frequency difference. The repetition frequency and mentioned frequency offset belong to main controlled parameters of the optical frequency comb. If these frequencies are electronically locked an ultrastable frequency standard (i.e. H-maser, Cs- or Rb- clock), its relative stability is transferred to the optical frequency domain. We present a complete digitally controlled signal processing chain for phase-locked loop (PLL) control of the offset frequency. The setup is able to overcome some dropouts caused by the femtosecond laser non-stabilities (temperature drifts, ripple noise and electricity spikes). It is designed as a two-stage control loop, where controlled offset frequency is permanently monitored by digital signal processing. In case of dropouts of PLL, the frequency-locked loop keeps the controlled frequency in the required limits. The presented work gives the possibility of long-time operation of femtosecond combs which is necessary when the optical frequency stability measurement of ultra-stable lasers is required. The detailed description of the modern solution of the PLL with remote management is presented.
Trvalý link: http://hdl.handle.net/11104/0241449