Outline: Yb optical frequency standard The fiber link Applications and fundamental physics

Transcription

1 Orologi ottici e link in fibra: metrologia primaria di frequenza e fisica fondamentale. Davide Calonico Physical Metrology Division ISTITUTO NAZIONALE DI RICERCA METROLOGICA [email protected] 1

2 Outline: Yb optical frequency standard The fiber link Applications and fundamental physics 2

3 Atomic clocks accuracy in the last 50 years First Cs beamclock (1955) First Cs fountain (1996) Cs fountain clocks (today) Comparisonand and dissemination Satellite techniques (1 day averaging) Best optical clocks (today) Fiber links (1 day averaging) 3

4 Cs cryogenic fountain INRIM ITCsF2 F. Levi, et al., Metrologia, 51, 270 (2014); S. R. Jeffertset al. PhysRev Lett, 112, (2014 ) Cryogenic structure@ 89 K σ y (τ)= τ -1/2 Accuracy: 1,

5 Yb Lattice Clock at INRIM 5

6 Blu Trap 399 nm Green Trap 556 nm Yb optical clock: operation cycle Lattice Trap 759 nm Clock 1S0-3P0 578 nm 1 mk (20 cm/s) 10 µk (1 cm/s) Yb 5 µk Blue MOT Up to 1x10 7 Yb171 Atoms MOT blu 150 ms loading time Oven temperature 400 C Green MOT 70% transfer efficiency 3 frequency stages Atoms temperature 10 µk Lattice and Clock Up to 4x10 4 atoms Usually 1x10 4 atoms 3 s lifetime in the trap Torino, 19 marzo

7 Yb optical clock: operation cycle Blu Trap 399 nm Green Trap 556 nm Lattice Trap 759 nm Clock 578 nm 1 mk (20 cm/s) 10 µk (1 cm/s) Yb 5 µk Blue MOT Up to 1x10 7 Yb171 Atoms MOT blu 150 ms loading time Oven temperature 400 C Green MOT 70% transfer efficiency 3 frequency stages Atoms temperature 10 µk Lattice and Clock Up to 4x10 4 atoms Usually 1x10 4 atoms 3 s lifetime in the trap Torino, 19 marzo

8 Clock Spectroscopy 0,6 Excitation Fraction 0,4 0,2 FWHM = 25 Hz 0, Frequency (Hz) Present possibilities: resolution <10-16 in10 4 s Target : 10x improvement 8

9 Ongoing Yb absolute measurement Optical Comb Accuracytarget: First, 1x0-17 Then, beyond Cryogenic Cs fountain H Masers Yb latttice clock 9

10 Outline: Yb optical frequency standard The fiber link Applications and fundamental physics 10

11 Italian Link for Time and Frequency Total Fiber Haul800 km Two Commercial Dark Fibers available/ DWDM and CWDM channels 11 bidirectional Erbium Doped Fiber Amplifier Fiber provided by Consortium GARR and Consortium TOP-IX 11 D. Calonico, KRISS, 2015 August 27

12 Link uncertainty contribution, 642x2 km There is not an offset between delivered and original signal at the 5x10-19 level D. Calonico et al., Applied Physics B, 117, 979(2014). 12

13 UNDER OPERATION SINCE 2013 UNDER OPERATION 2016 LIFT FIBER LINK: extension D. Calonico et al., European Physics Letters 110, (2015) 13

14 Outline: Yb optical frequency standard The fiber link Applications and fundamental physics 14

15 LIFT present impact on research Frejus: Relativistic Geodesy Firenze: Atomic and Molecular Physics Bologna Radio-astronomy VLBI Cagliari Noto Space Geodesy Matera 15

16 LIFT present impact on research Frejus: Relativistic Geodesy Testing GR Firenze: Atomic and Molecular Physics INRIM/LENS Yb degenerate gas spectroscopy Bologna Radio-astronomy VLBI Cagliari INRIM/INAF/ASI Common clock VLBI Noto Space Geodesy INRIM/CNR Cold molecules me/mp stability test Matera 16

17 Towards common clock VLBI: extension to Matera FREJUS TORINO BOLOGNA FUCINO MATERA Space Geodesy Center Bepi Colombo 17

18 Towards radioastronomical application: Medicina H- Maser vs INRIM fountain measured in real time using the fiber link (This result is not possible using Satellites tehniques) 18 Accepted tbp on IEEE T-UFFC

19 Testing Einstein geodetic motion INRIM-ASI- ESA (July January 2019) Microwave Link Torino-ISS Optical Link Torino-Matera Laser Ranging Matera-ISS High accurate Atomic clocks 1500 km optical fiber Space Geodesy Center Bepi Colombo

20 Relativistic Geodesy on the Alps Given high accurate clocks and a fiber link connection, we can directly measure the potential difference at levels better than 10 cm (10-17 ) on short timescales (hours) Frejus Tunnel,1263 m 1000 m height difference means frequency offset to be studied at a level better than (test level < 10-4 ) Torino, 240 m 20

21 Relativistic Geodesy on the Alps LSM 150 km FIBER (highway) INRIM NPL comb D. Calonico, KRISS, 2015 August 27 21

22 Optical Links in Europe D. Calonico et al., European Physics Letters 110, (2015) 22

23 Conclusionsand perspectives o o o INRIM ITCsF2 primary frequencystandard with 1.7x10-16 accuracy. The Yb frequency standard is now under characterization. Up to 800 km of fiber connect different scientific sites by a coherent link NEXT steps: A second Yb clock The link extension in South Italy (Space Geodesy) and to Paris Perspectives: Relativistic Gedodesy Radioastronomy High accuracy spectroscopy Redefinition of the second 23

24 Thanks to... Thank you for your attention This work was supported by: the Italian Ministry of Research MIUR under Progetti Premiali programme and PRIN ZJJBLX project; the European Metrology Research Programme (EMRP) under SIB-02 NEAT-FT and SIB55-ITOC. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. 24

25 INRIM Atomic Frequency Standards Group 25