Other Clocks

General

Optical atomic clocks, N. Poli et al., arXiv:1401.2378v2 (2014)

Optical atomic clocks, A.D. Ludlow et al., Reviews of modern physics 87 (2015)

Fritz Riehle, Frequency Standards, WILEY-VCH Verlag GmbH & Co. KGaA, 2004

Best Clock so far (Stand 11/2016) http://www.nature.com/nature/journal/v506/n7486/pdf/nature12941.pdf doi:10.1038/nature12941

Systematic Evaluation for this http://www.nature.com/articles/ncomms7896.pdf

Best Clock Comparison so far (Stand 11/2016) Comparison of Two Independent Sr Optical Clocks with 1×10−17 Stability at 10^3 s: physrevlett.109.230801.pdf

Elements

Mercury:

Comparing a mercury optical lattice clock with microwave and optical frequency standards, R. Tyumenev et al., arXiv:1603.02026v2 [physics.atom-ph] 13 Nov 2016

Application

Realization of a timescale with an accurate optical lattice clock: optica-3-6-563.pdf

Cavities

Summary of the best cavities

General

Making optical atomic clocks more stable with 10−16-level laser stabilization, V. Jiang et al.,Nature Photonics 5, 158–161 (2011)

Relevant effects influencing frequency stability

Vibration:

Simple vibration-insensitive cavity for laser stabilization at the 10^-16 level, J. Keller et al., Appl. Phys. B 116, 203–210 (2014)

Thermal-Noise:

Thermal-Noise Limit in the Frequency Stabilization of Lasers with Rigid Cavities, K. Numata et al., PRL 93, 250602 (2004)

Thermal noise in optical cavities revisited, T. Kessler et al., J. Opt. Soc. Am. B Vol. 29, No. 1 (2012)

Residual amplitude modulation:

Reduction of residual amplitude modulation to 1 × 10-6 for frequency modulation and laser stabilization, W. Zhang et al., Optics Letters Vol. 39, No. 7 (2014)

Investigation and cancellation of residual amplitude modulation in fiber electro-optic modulator based frequency modulation gas sensing technique, Z. Li et al., Sensors and Actuators B 196, 23–30 (2014)

Residual amplitude modulation in interferometric gravitational wave detector, K. Kokeyama et al., J. Opt. Soc. Am. A Vol. 31, No. 1 (2014)

Residual Amplitude Modulation in Interferometric Gravitational Wave Detectors, K. Kokeyama et al., aXiv:1309.4522v1 [gr-qc] 18 Sep 2013

Length

7 cm:

Compact, thermal-noise-limited optical cavity for diode laser stabilization at 1×10−15, A. D. Ludlow et al., Optics Letters Vol. 32, Issue 6, pp. 641-643 (2007)

10 cm:

A compact, robust, and transportable ultra-stable laser with a fractional frequency instability of 1 × 10−15, Q. F. Chen et al., REVIEW OF SCIENTIFIC INSTRUMENTS 85, 113107 (2014)

48 cm:

8 × 10−17 fractional laser frequency instability with a long room-temperature cavity, S. Häfner et al., Optical Letters Vol. 40, No. 9 (2015)

Mirror layers

Crystaline coatings:

Tenfold reduction of Brownian noise in high-reflectivity optical coatings, Garrett D. Cole et al., Nature Photonics 7, 644–650 (2013)

Other geometries

Cubic geometry:

Force-insensitive optical cavity, S. Webster et al., Optics Letters Vol. 36, Issue 18, pp. 3572-3574 (2011)

PTB took the NPL-design and updated it for a better longterm stability (see Häfner PHD-thesis, Chapter 4.2)

Cryogenic single-crystal optical cavities:

Ultrastable laser with average fractional frequency drift rate below 5 × 10−19/s, C. Hagemann et al., Optics Letters Vol. 39, No. 17 (2014)

A sub-40-mHz-linewidth laser based on a silicon single-crystal optical cavity, T. Kessler et al., Nature Photonics Vol. 6, 687-692 (2012)

Applications

Transfer of stability:

Providing 10−16 Short-Term Stability of a 1.5-μm Laser to Optical Clocks, C. Hagemann et. al., IEEE Transactions on instrumentation and measurement, VOL. 62, NO. 6 (2013)