Enhanced link availability for free space optical time-frequency transfer using adaptive optic terminals

Optical time and frequency transfer offers extremely high precision wireless synchronization across multiple platforms for untethered distributed systems. While large apertures provide antenna gain for wireless systems which leads to robust link budgets and operation over increased distance, turbulence disrupts the beam and limits the full realization of the antenna gain. Adaptive optics can correct for phase distortions due to turbulence which potentially increases the total gain of the aperture to that for diffraction-limited operation. Here, we explore the use of adaptive optics terminals for free-space time and frequency transfer. We find that the requirement of reciprocity in a two-way time and frequency transfer link is maintained during the phase compensation of adaptive optics, and that the enhanced link budget due to aperture gain allows for potential system operation over ranges of at least tens of kilometers.

[1]  Junho Shin,et al.  Frequency comb-based microwave transfer over fiber with 7×10(-19) instability using fiber-loop optical-microwave phase detectors. , 2014, Optics letters.

[2]  A. Ephremides,et al.  A design concept for reliable mobile radio networks with frequency hopping signaling , 1987, Proceedings of the IEEE.

[4]  Esther Baumann,et al.  Optical two-way time and frequency transfer over free space , 2013 .

[5]  I Coddington,et al.  Invited Article: A compact optically coherent fiber frequency comb. , 2015, The Review of scientific instruments.

[6]  Christian Chardonnet,et al.  Ultra-stable long distance optical frequency distribution using the Internet fiber network and application to high-precision molecular spectroscopy , 2012, Optics express.

[7]  L. Nenadovic,et al.  Rapid and precise absolute distance measurements at long range , 2009 .

[8]  J. Shapiro.  Reciprocity of the Turbulent Atmosphere , 1971 .

[9]  A. L. Puryear,et al.  Reciprocity-enhanced optical communication through atmospheric turbulence — Part I: Reciprocity proofs and far-field power transfer optimization , 2012, IEEE/OSA Journal of Optical Communications and Networking.

[10]  Jean-Daniel Deschênes,et al.  A compact optically coherent fiber frequency comb , 2015 .

[11]  David L. Mills,et al.  Internet time synchronization: the network time protocol , 1991, IEEE Trans. Commun..

[12]  Judah Levine,et al.  A review of time and frequency transfer methods , 2008 .

[13]  Robert K. Tyson,et al.  Adaptive Optics Engineering Handbook , 1999 .

[14]  Jean-Daniel Deschênes,et al.  Optical two-way time synchronization at the femtosecond level over a 4-km free space link , 2015 .

[15]  Christian Chardonnet,et al.  Simultaneous remote transfer of accurate timing and optical frequency over a public fiber network , 2012, 2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC).

[16]  Zhigang Li,et al.  Two-way satellite time and frequency transfer networks in Pacific Rim region , 2001, IEEE Trans. Instrum. Meas..

[17]  Ming Xin,et al.  One-femtosecond, long-term stable remote laser synchronization over a 3.5-km fiber link , 2014, 2014 Conference on Lasers and Electro-Optics (CLEO) - Laser Science to Photonic Applications.

[18]  J. Degnan,et al.  Optical antenna gain. 1: transmitting antennas. , 1974, Applied optics.

[19]  A. Mink,et al.  Quantum key distribution with 1.25 Gbps clock synchronization , 2004, InternationalQuantum Electronics Conference, 2004. (IQEC)..

[20]  Hugo Bergeron,et al.  Synchronization of Distant Optical Clocks at the Femtosecond Level , 2015, 1509.07888.

[21]  Esther Baumann,et al.  Optical phase noise from atmospheric fluctuations and its impact on optical time-frequency transfer , 2014 .

[22]  C Clivati,et al.  Frequency transfer via a two-way optical phase comparison on a multiplexed fiber network. , 2013, Optics letters.

[23]  Thomas Udem,et al.  Optical frequency transfer over a single-span 1840 km fiber link , 2013, CLEO: 2013.

[24]  T. Divoux,et al.  Networked control using GPS synchronization , 2006, 2006 American Control Conference.

[25]  Raymond M. Sova,et al.  80 Gb/s free-space optical communication demonstration between an aerostat and a ground terminal , 2006, SPIE Optics + Photonics.

[27]  J. Laskar,et al.  Quantum physics exploring gravity in the outer solar system: the SAGAS project , 2007, 0711.0304.

[28]  H. Vincent Poor,et al.  Collaborative beamforming for distributed wireless ad hoc sensor networks , 2005, IEEE Transactions on Signal Processing.

[29]  Stuart A. Collins,et al.  Behavior of the Refractive-Index-Structure Parameter near the Ground* , 1971 .

[30]  L. Godara.  Application of antenna arrays to mobile communications. II. Beam-forming and direction-of-arrival considerations , 1997, Proc. IEEE.

[31]  Saurabh Ganeriwal,et al.  Timing-sync protocol for sensor networks , 2003, SenSys '03.

[32]  Till Rosenband,et al.  Field-test of a robust, portable, frequency-stable laser. , 2011, Optics express.

[33]  Juan C Juarez,et al.  Antenna gain of actively compensated free-space optical communication systems under strong turbulence conditions. , 2014, Optics express.