White Rabbit to disseminate time on an active telecom network?

Transcription

1 White Rabbit to disseminate time on an active telecom network? Namneet Kaur, Florian Frank, Philip Tuckey and Paul-Eric Pottie some slides contents data thanks to courtesy of Anders Wallin & Mikko Merimaa

2 Outline 1. Introduction LNE-SYRTE : the french National metrology institutes Time and frequency transfer at LNE-SYRTE New needs and new methods Optical frequency domain: recent achievements 3. Time dissemination Point to point vs multi-user White Rabbit for time dissemination on an active network Motivations and goals Just get started...only some preliminary tests presented

3 LNE-SYRTE operational facilities Microwave satellite links Timescale Microwave clocks Optical oscillators Optical combs Optical clocks Microwave oscillators Optical links

4 Atomic clocks performances over 70 years 1x x x10-12 Essen & Parry H Optical Clocks Optical Frequency Combs Ca H 1x10-13 H Accuracy 1x x Redefinition of SI second Cs Clocks (microwave) Atomic fountains H Hg +,Yb +,Ca Sr +,Yb + Sr Hg +,Yb + Sr Hg + Al + Sr Year

5 Means to compare clocks Satellite Link (1s) 2x10-16 (1d) NMI in Europe NMI A Atomic clock 1 800< distance <1500 km B Atomic clock 2 Stability(1s) <10-13 Accuracy <10-16 Transportable clock (FOM) (1s) 4x10-16 (1d)

6 Means to compare clocks Satellite Link (1s) 2x10-16 (1d) NMI Optical Fiber Link in Europe NMI A Atomic clock 1 800< distance <1500 km B Atomic clock 2 Stability(1s) <10-13 Accuracy <10-16 Transportable clock (FOM) (1s) 4x10-16 (1d)

7 Optical fiber links Seminal works: Primas et al, Proc 20 th PTTI, 1988, Ma et al., OL 1994 Active noise compensation after one round-trip Strong hypothesis : noises forth and back are the same 2 ends at the same place (for link stability measurement) Local end %&" #" Remote end Ultrastable µm laser Atomic optical clocks OC!$" Noise Correction #"! " Accumulated Phase noise!" OC %&" #"!" Link instability measurement OC OC Optical coupler

8 Frequency transfer : the optical way Satellite links don t meet optical optical clocks comparisons requirements μw clocks Modified Allan Deviation optical clocks TW-CP GPS GPS IPP Optical links Integration time (s) O. Lopez et al., «F&T transfer for metrology and beyond (...)», Comptes Rendus Physique, In press (2015)

9 Part II : optical frequency transfer recent achievements

10 A story started a decade ago Gesine Grosche Anne Amy-Klein Christian Chardonnet Harald Schnatz Giorgio Santarelli Olivier Lopez

11 Range increase for fiber links in Europe Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE Year

12 Range increase for fiber links in Europe Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE over internet network Year

13 Range increase for fiber links in Europe Brillouin amplifiers Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE over internet network Year

14 Range increase for fiber links in Europe Brillouin amplifiers Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE over internet network Regeneration Year

15 Range increase for fiber links in Europe Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE Brillouin amplifiers over internet network Regeneration Two-way Year

16 Range increase for fiber links in Europe Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE Brillouin amplifiers over internet network Regeneration World record Two-way Year

17 Range increase for fiber links in Europe Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE Brillouin amplifiers over internet network Regeneration World record Two-way FBA remote Year

18 Range increase for fiber links in Europe Fiber links range (km) Threshold to enable clock comparisons in Europe LKB-SYRTE Brillouin amplifiers over internet network Regeneration World record Two-way FBA remote Year

19 Frequency transfer : the optical way Only CW Optical frequency dissemination / comparison represented ICOF PTB/MPQ (GéANT) 500 km MODANE MEDICINA LIFT 2 «big» link projects in 2012 : REFIMEVE+, LIFT target optical frequency dissemination > 4000 km

20 Time and Frequency transfer with fiber links in Europe Time &/or Frequency transfer : Combs RF + pps SONET, SDH, WR SP-MIKES : 1000 km MIKES-Kajaani : 1000 km UFE-BEV : 540 km GUM-AOS : 420 km VSL-VUA : 208 km NPL : 118 km Review article O. Lopez et al., Comptes Rendus Physique, 16 (5), pp (2015) Suggested focus on : P. Krehlik, et al.; Metrologia, 52, pp , (2015) Parker et al., 53,(35), (2014) G. Marra et al., 20 (2), (2012) NEAT FT 700 km NPL SYRTE VSL INRIM PTB MIKES SP AOS UFE BEV GUM

21 The 1st Sr-Sr comparison by long haul fiber links PTB Team, LPL Team, SYRTE Team, RENATER, Université de Strasbourg, LP2N are : M. Abgrall, A. Al-Masoudi, A. Amy-Klein, E. Bookjans, S. Bilicki, E. Camisard, C. Chardonnet, N. Chiodo, S. Dörscher, C. Grebing, G. Grosche, S. Häfner, A. Koczwara, S. Koke, A. Kuhl, Y. Le Coq, T. Legero, R. Le Targat, C. Lisdat, J. Lodewyck, M. Lours, O. Lopez, F. Meynadier, B. Moya, D. Nicolodi, P.-E. Pottie, N. Quintin, S. Raupach, J.-L. Robyr, G. Santarelli, C. Shi, H. Schnatz, F. Stefani, U. Sterr, F. Wiotte

22 An optical methodology Paris Strasbourg Braunschweig Counting the RF of the beat notes with the fs combs Sr F1 Comb 194,4 THz F3 optical Two-way F4 F5 Comb Sr F2 UTC(OP) GPS time UTC(PTB) Absolute frequency difference without SI-Hz

23 Sr-clocks comparison SYRTE-PTB C. Lisdat et al «A clock network for geodesy and fundamental science» : arxiv:

24 Sr-clocks comparison SYRTE-PTB

25 Sr-clocks comparison SYRTE-PTB Frequency instability Sr PTB -Sr SYRTE 2x10-17 (5000 to s) Accuracy : Sr PTB -Sr SYRTE agreement (4.7±5)x10-17 Two fully independent system in agreement within the statistical error bars. Black body shift, light shift, AC Stark shift and collisions well controled on two different setups Optical links demonstrates their ability to compare clock with superior abilities to any other methods Gravitational redshift is taken into account. Confirm the proper correction of relativistic effects Precise levelling of the clocks thanks to the ITOC campaign

26 Need for F&T metrology : dissemination Frequency metrology: Geodesy Access to ultra precise reference frequencies for remote user. Applied dimensional measurements: Traceability of the unit of length for interferometric measurements. Astronomy: Phase traceable signals for the synchronization of radio telescopes Several projects are going on (REFIMEVE+, LIFT...) Broadband communication technology: Astronomy Provision of reference signals with low-jitter for synchronization Large research infrastructures (ESA, DESY, CERN, GSI): Time and frequency dissemination in ground stations Industry : wireless, optical telecom., Galileo GNSS ground segment 2013 : two experiments start with WR on long hauls 2015 : start of

27 Part III : Time dissemination over a national network Goal # 1 : high performance for next generation of optical time scale comparison, test of fundamental physics Goal # 2 : time dissemination to civil society Alternative to GNSS signal Towards a fiber based time service? Necessary renewed approach NTP, PTP WR lot of activities worldwide with «custom» solutions Collaboration with RENATER for proof of principle demonstrations

28 White LNE-SYRTE Multi user : Point-to-many Explore the wide scale approach : Comply with Telecom backbone architecture : 1 wavelength, 2 fibers Benefits from uni-directional amplification, no backbone adaptation Data traffic on other channels Differential chromatic dispersion is huge with 1310/1490 SFP pairs! DWDM channels to use lasers with smaller frequency instability Delay assymetry reduction from 2 ns to 70 ps over 1000 km Interoperability of networks : traceability, security Investigate the feasibility of calibrated time service on long haul LAN Achievable accuracy in time?

29 Experimental set up H-Maser signal 1GHz distribution SYRTE 10 MHz local reference & distribution 10MHz REF Grand Master (GM) 10 m Master (M) PPS generation & distribution PPS REF 25 km Time interval counter SR 620 SPEC (Slave) 10 MHz clock signal Phase noise analysis microsemi

30 Phase noise : Grand master clock signal Free SYRTE Free VTT SYRTE VTT VTT = ex-mikes, cf. A. Wallin

31 Phase noise : Grand master clock signal Free SYRTE Free VTT SYRTE VTT VTT = ex-mikes, cf. A. Wallin

32 Time intervals : GM & SPEC vs PPS REF GM board No fiber care to temperature! SPEC board after 25 km of fiber spools uni-directional, 2 fibers Wavelength = 1541 nm Time intervalle (ps) Time intervalle (ps) Measurement time (hours) Measurement time (hours)

33 Time deviation : GM, & SPEC board after 25 km (s) Time Deviation SYRTE GM vs REF (no fiber) VTT GM vs REF (no fiber) VTT SPEC+WRS+SPEC 1.2 km km SYRTE WRS+WRS+SPEC km + 25 km VTT = ex-mikes, cf. A. Wallin Integration time (s)

34 Allan deviation : GM, & SPEC board after 25 km GM board No fiber care to temperature! SPEC board after 25 km of fiber spools uni-directional, 2 fibers Wavelength = 1541 nm Overlapping Allan Deviation GM vs PPS REF SPEC board - 25 km uni-dir Active H-maser Fit 7E-11/tau M. Lipinski 2E-10 /tau A. Wallin 1.5E-10 /tau with improved LO? 86 km free running fiber 100 MHz Integration time (s) Modified Allan Deviation GM vs PPS REF SPEC board - 25 km uni-dir Fit 7E-11 /tau 3 / Integration time (s)

35 Work on calibration - test asymetry H-Maser signal 1GHz distribution SYRTE 10 MHz local reference & distribution PPS generation & distribution Time interval counter SR 620 PPS REF up Grand Master (GM) 10 m(+25 km) down Master (M) Time difference (ps) rtt compute rtt - TIC for 1 added spool on way up or on way down, with correction for SFPs asymetry AVG = -15 ps +/- 30 ps TIC Measurement #

36 Work on calibration - test asymetry H-Maser signal 1GHz distribution SYRTE 10 MHz local reference & distribution PPS generation & distribution Time interval counter SR 620 PPS REF up Grand Master (GM) 10 m(+25 km) down Master (M) Time difference (ps) rtt compute rtt - TIC for 1 added spool on way up or on way down, with correction for SFPs asymetry AVG = -15 ps +/- 30 ps TIC Measurement #

37 Work on calibration - test asymetry H-Maser signal 1GHz distribution SYRTE 10 MHz local reference & distribution PPS generation & distribution Time interval counter SR 620 PPS REF up Grand Master (GM) 10 m(+25 km) down Master (M) Time difference (ps) rtt compute rtt - TIC for 1 added spool on way up or on way down, with correction for SFPs asymetry AVG = -15 ps +/- 30 ps TIC Measurement #

38 Work on calibration - test asymetry H-Maser signal 1GHz distribution SYRTE 10 MHz local reference & distribution PPS generation & distribution Time interval counter SR 620 PPS REF up Grand Master (GM) 10 m(+25 km) down Master (M) Time difference (ps) rtt compute rtt - TIC for 1 added spool on way up or on way down, with correction for SFPs asymetry AVG = -15 ps +/- 30 ps TIC Measurement #

39 Work on calibration - test asymetry H-Maser signal 1GHz distribution SYRTE 10 MHz local reference & distribution PPS generation & distribution Time interval counter SR 620 PPS REF up Grand Master (GM) 10 m(+25 km) down Master (M) Time difference (ps) rtt compute rtt - TIC for 1 added spool on way up or on way down, with correction for SFPs asymetry AVG = -15 ps +/- 30 ps TIC Measurement #

40 Conclusions First remote optical clock comparison PTB-SYRTE achieved in 2015 Fortunately (?) no shift within the statistical uncertainty of the comparison (clock limited) entering a new era of T/F metrology White Rabbit experiment just OP long-haul WR, uni-directional configuration, DWDM active telecommunication network preliminary specifications, just start on calibration plans to deploy at a national scale

41 Thank you for attention Namneet Kaur Florian Frank Philip Tuckey Questions?

42 Some phase jumps sometimes? Time intervalle (ps) Measurement time (hours)

43 Joint T&F Transfer with Active Stabilization of the Propagation delay (bi directional) P. Krehlik, Ł. Śliwczyński, Ł. Buczek, M. Lipiński, AGH University of Science and Technology, Institute of Electronics, Kraków, Poland, IEEE Trans. on Instr. and Meas. (2012). 480-km fiber + 8 bi dir EDFAs 10-MHz + 1pps joint transfer through intensity modulation of the optical carrier; stabilized laser Roundtrip propagation in the same fiber for noise correction Active stabilization of the propagation delay through a variable delay module (DLL)

44 Delay-stabilized time transfer 420-km loop fiber (Polish Telecom -Krakow-Skawina and back) Accuracy 100 ps, Stability (1d) : 0.3 ps