10-GHz Self-Referenced Optical Frequency Comb
ABSTRACT The femtosecond laser-based frequency comb has played a key role in high-precision optical frequency metrology for a decade. Although often referred to as a precise optical frequency ruler, its tick marks are in fact too densely spaced for direct observation and individual use, limiting important applications in spectroscopy, astronomy, and ultrafast electromagnetic waveform control. We report on a femtosecond laser frequency comb with a 10-gigahertz repetition rate that creates a stabilized output spectrum with coverage from 470 to 1130 nanometers. The individual modes can be directly resolved with a grating spectrometer and are visible by eye.
Full-textDOI: · Available from: Dirk C. Heinecke, Aug 12, 2015
- SourceAvailable from: David Kielpinski
[Show abstract] [Hide abstract]
- "In principle, high repetition rate is readily obtained by reducing the length of the laser resonator. This approach has been demonstrated for solid-state  and fiber lasers , but is inherently limited by technical constraints on miniaturization and the nonlinear dynamics of the mode-locking mechanism. These difficulties become more prominent as the repetition rate is pushed higher. "
ABSTRACT: We have used injection locking to multiply the repetition rate of a passively mode-locked femtosecond fiber laser from 40 MHz to 1 GHz while preserving optical phase coherence between the master laser and the slave output. The system is implemented almost completely in fiber and incorporates gain and passive saturable absorption. The slave repetition rate is set to a rational harmonic of the master repetition rate, inducing pulse formation at the least common multiple of the master and slave repetition rates.Optics Express 01/2012; 20(3):2717-24. DOI:10.1364/OE.20.002717 · 3.53 Impact Factor
[Show abstract] [Hide abstract]
- "With a half-wave plate the polarisation is adjusted for maximum broadening in the microstructured fiber. The supercontinuum spectrum is shown in Fig. 2. In early experiments  the fiber-coupling stability limited the operation of the system to intervals of about 10 minutes. The large average power in combination with tight focussing into the small fiber core leads to heating of the fiber and thermal instabilities in coupling efficiency and output polarization. "
ABSTRACT: This paper shows the experimental details of the stabilization scheme that allows full control of the repetition rate and the carrier-envelope offset frequency of a 10 GHz frequency comb based on a femtosecond Ti:sapphire laser. Octave-spanning spectra are produced in nonlinear microstructured optical fiber, in spite of the reduced peak power associated with the 10 GHz repetition rate. Improved stability of the broadened spectrum is obtained by temperature-stabilization of the nonlinear optical fiber. The carrier-envelope offset frequency and the repetition rate are simultaneously frequency stabilized, and their short- and long-term stabilities are characterized. We also measure the transfer of amplitude noise of the pump source to phase noise on the offset frequency and verify an increased sensitivity of the offset frequency to pump power modulation compared to systems with lower repetition rate. Finally, we discuss merits of this 10 GHz system for the generation of low-phase-noise microwaves from the photodetected pulse train.Optics Express 09/2011; 19(19):18440-51. DOI:10.1364/OE.19.018440 · 3.53 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The high power per mode of a recently developed 10 GHz femtosecond Ti:sapphire frequency comb permits nonlinear Doppler-free saturation spectroscopy in 87Rb with a single mode of the comb. We use this access to the natural linewidth of the rubidium D2 line to effectively stabilize the optical frequencies of the comb with an instability of 7×10−12 in 1 s of averaging. The repetition rate is stabilized to a microwave reference leading to a stabilized and atomically referenced comb. The frequency stability of the 10 GHz comb is characterized using optical heterodyne with an independent self-referenced 1 GHz comb. In addition, we present alternative stabilization approaches for high repetition rate frequency combs and evaluate their expected stabilities.Physical Review A 11/2009; 80(5). DOI:10.1103/PhysRevA.80.053806 · 2.99 Impact Factor