Analysis of frequency noise properties of 729 nm extended cavity diode laser with unbalanced Mach-Zehnder interferometer

0468520 - ÚPT 2017 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Pham, Minh Tuan - Čížek, Martin - Hucl, Václav - Lazar, Josef - Hrabina, Jan - Řeřucha, Šimon - Lešundák, Adam - Obšil, P. - Filip, R. - Slodička, L. - Číp, Ondřej
Analysis of frequency noise properties of 729 nm extended cavity diode laser with unbalanced Mach-Zehnder interferometer.
20th Slovak-Czech-Polish Optical Conference on Wave and Quantum Aspects of Contemporary Optics (Proceedings of SPIE 10142). Bellingham: SPIE, 2016, s. 1-5, č. článku 101420E. ISSN 0277-786X.
[Slovak-Czech-Polish Optical Conference on Wave and Quantum Aspects of Contemporary Optics /20./. Jasná (SK), 05.09.2016-09.09.2016]
Institucionální podpora: RVO:68081731
Klíčová slova: Mach-Zehnder interferometer * semiconductor lasers * frequency combs * optical resonators * servomechanisms
Obor OECD: Optics (including laser optics and quantum optics)
http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2595350

We report on the frequency noise investigation of a linewidth-suppressed Extended Cavity Diode Laser (ECDL), working at 729 nm. Since the ECDL is intended as an excitation laser for the forbidden transition in a trapped and laser cooled 40Ca+ ion, an Hz-level linewidth is required. We present the experimental design that comprises a two-stage linewidth narrowing and a facility for frequency and noise analysis. The linewidth is first narrowed with a phase lock loop of the ECDL onto a selected component of an optical frequency comb where the frequency noise was suppressed with a fast electronic servo-loop controller that drives the laser injection current with a high bandwidth. The second stage comprises locking the laser onto a selected mode of a high-finesse passive optical cavity. The frequency analysis used an unbalanced Mach-Zehnder interferometer with a fiber spool inserted in the reference arm in order to give a general insight into the signal properties by mixing two separated beams, one of them delayed by the spool, and processing it with a spectral analyzer. Such a frequency noise analysis reveals what are the most significant noises contributions to the laser linewidth, which is a crucial information in field of ion trapping and cooling. The presented experimental results show the effect of the linewidth narrowing with the first stage, where the linewidth of ECDL was narrowed down to a kHz level.
Trvalý link: http://hdl.handle.net/11104/0266452