Remote distribution of a mode-locked pulse train with sub 40-as jitter

Department of Physics and Astronomy, University of British Columbia - Vancouver, Vancouver, British Columbia, Canada
Optics Express (Impact Factor: 3.49). 01/2007; 14(25):12134-44. DOI: 10.1364/OE.14.012134
Source: PubMed


Remote transfer of an ultralow-jitter microwave frequency reference signal is demonstrated using the pulse trains generated by a mode-locked fiber laser. The timing jitter in a ~ 30-m fiber link is reduced to 38 attoseconds (as) integrated over a bandwidth from 1 Hz to 10 MHz via active stabilization which represents a significant improvement over previously reported jitter performance. Our approach uses an all-optical generation of the synchronization error signal and an accompanying out-of-loop optical detection technique to verify the jitter performance.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Coherent optical sources in the 1550 nm region of the spectrum have a number of applications in frequency metrology, stable frequency transfer, precision spectroscopy and remote sensing. A narrow-linewidth (~ 1 Hz) single-frequency source can be generated by phase-locking a cw fiber laser to a stable optical cavity. A comb of such narrow linewidth sources can be generated by phase-locking a mode-locked, femtosecond fiber laser to a single narrow cw source. We will discuss the current development of our narrow linewidth cw and pulsed sources at 1550 nm and some of the applications that can benefit from such coherent sources.
    No preview · Article · Sep 2007 · Proceedings of SPIE - The International Society for Optical Engineering
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The rapid development of femtosecond optical frequency combs over the last decade has brought together ultrastable phase control of both cw and mode-locked lasers and ultrafast time-domain applications. Frequency-domain laser stabilization techniques applied to the ultrashort-pulse trains emitted by a mode-locked laser result in a level of optical phase control previously achievable only for radio frequencies and microwaves. I present our work extending such control to mode-locked lasers for both timing and frequency stabilization applications of optical frequency combs. I first present a microwave technique for synchronizing two independent modelocked lasers at a level of timing precision less than the duration of an optical cycle, below 1 fs of residual rms timing jitter. Using these synchronized pulses, simultaneous sum- and difference-frequency generation of 400-nm and tunable mid-infrared fs pulses is demonstrated, opening the door for broadband coherent control of atomic and molecular systems. For frequency metrology, I report on an offset-free clockwork for an optical clock based on the 3.39-mum transition in methane. The clockwork's simplicity leads to a robust and reliable table-sized optical frequency reference with instability approaching a few parts in 1014. Then I describe a directly-octave-spanning, self-referenced Ti:sapphire laser employed as the robustly-running phase-coherent clockwork for an 87Sr optical lattice clock. The optical comb distributes the 2-s coherence time of the 698-nm ultrastable clock laser to its modes spanning the visible and near-IR spectrum, and is therefore simultaneously used as a hub for measuring absolute frequencies or frequency ratios between the Sr clock and other remotely-located microwave and optical atomic standards. Finally, I report on the transfer of ultrastable frequency references, both microwave and optical, through 10-km-scale optical fiber links. Actively stabilizing the optical phase delay of such a fiber link, we are able to transfer a cw optical frequency standard with a transfer instability of 6x10 -18 at 1 s, more than two orders of magnitude lower than reported for any fiber link of similar length. Phase coherence between ends of the fiber link is preserved at the mHz linewidth level, and the transfer phase noise corresponds to less than 80 attoseconds of rms timing jitter integrated from 10 mHz to 30 MHz.
    Preview · Article · Jan 2007
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Three distinct techniques exist for distributing an ultrastable frequency reference over optical fibers. For the distribution of a microwave frequency reference, an amplitude-modulated continuous wave (cw) laser can be used. Over kilometer-scale lengths this approach provides an instability at 1 s of approximately 3 x 10(-14) without stabilization of the fiber-induced noise and approximately 1 x 10(-14) with active noise cancellation. An optical frequency reference can be transferred by directly transmitting a stabilized cw laser over fiber and then disseminated to other optical and microwave regions using an optical frequency comb. This provides an instability at 1 s of 2 x 10(-14) without active noise cancellation and 3 x 10(-15) with active noise cancellation [Recent results reduce the instability at 1 s to 6 x 10(-18).] Finally, microwave and optical frequency references can be simultaneously transmitted using an optical frequency comb, and we expect the optical transfer to be similar in performance to the cw optical frequency transfer. The instability at 1 s for transfer of a microwave frequency reference with the comb is approximately 3 x 10(-14) without active noise cancellation and <7 x 10(-15) with active stabilization. The comb can also distribute a microwave frequency reference with root-mean-square timing jitter below 16 fs integrated over the Nyquist bandwidth of the pulse train (approximately 50 MHz) when high-bandwidth active noise cancellation is employed, which is important for remote synchronization applications.
    Full-text · Article · Mar 2007 · Review of Scientific Instruments
Show more