Subhertz linewidth laser by locking to a fiber delay line.

An ultralow-noise, subhertz 1.55 μm erbium-doped fiber laser that is locked on an all-fiber-based Michelson interferometer is presented in this paper. The interferometer uses 500 m SMF-28 optical fiber and an acousto-optic modulator to allow heterodyne detection. By comparing two identical laser systems, a 0.67 (0.21) Hz linewidth beat-note signal is achieved and we obtain fractional frequency instability of 7×10(-15) at short timescales (0.1-1 s). The frequency noise power spectral density of two identical lasers is below -1  dB Hz(2)/Hz at 1 Hz and it reaches -18  dB Hz(2)/Hz from 200 Hz to 1 kHz.

[1]  Joshua R. Smith,et al.  LIGO: The laser interferometer gravitational-wave observatory , 2006, QELS 2006.

[2]  S. Foster,et al.  Fundamental Thermal Noise in Distributed Feedback Fiber Lasers , 2007, IEEE Journal of Quantum Electronics.

[3]  Lingze Duan,et al.  Intrinsic thermal noise of optical fibres due to mechanical dissipation , 2010 .

[4]  K. Wanser,et al.  Fundamental phase noise limit in optical fibres due to temperature fluctuations , 1992 .

[5]  Giorgio Santarelli,et al.  Ultralow-frequency-noise stabilization of a laser by locking to an optical fiber-delay line. , 2009, Optics letters.

[6]  E. Peik,et al.  Stray-field-induced quadrupole shift and absolute frequency of the 688-THz {sup 171}Yb{sup +} single-ion optical frequency standard , 2009 .

[7]  André Clairon,et al.  An agile laser with ultra-low frequency noise and high sweep linearity. , 2009, Optics express.

[8]  Lei Chen,et al.  A sub-40-mHz-linewidth laser based on a silicon single-crystal optical cavity , 2011, Nature Photonics.

[9]  M. Kirchner,et al.  Generation of ultrastable microwaves via optical frequency division , 2011, 1101.3616.

[10]  John L. Hall,et al.  Laser phase and frequency stabilization using an optical resonator , 1983 .

[11]  Helena Armandula,et al.  Thermal noise from optical coatings in gravitational wave detectors. , 2006, Applied optics.

[12]  W. Itano,et al.  Measurement of the (199)Hg+ 5d9 6s2 (2)D(5/2) electric quadrupole moment and a constraint on the quadrupole shift. , 2005, Physical review letters.

[13]  Jun Ye,et al.  Sr Lattice Clock at 1 × 10–16 Fractional Uncertainty by Remote Optical Evaluation with a Ca Clock , 2008, Science.

[14]  D. Wineland,et al.  Frequency comparison of two high-accuracy Al+ optical clocks. , 2009, Physical review letters.

[15]  R. E. Bartolo,et al.  Thermal Phase Noise Measurements in Optical Fiber Interferometers , 2012, IEEE Journal of Quantum Electronics.

[16]  A. Nevsky,et al.  A laboratory test of the isotropy of light propagation at the 10−17 level , 2009, CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference.