Outline Review of the CSO at Femto-ST The ELISA project The ULISS - PowerPoint PPT Presentation

ULISS project – First comparison of two cryocooled sapphire oscillators at the 10 − 15 level Serge Grop 1 , Benoit Dubois 1 , Jean Louis Masson 2 , Gregory Haye 1,2 , Pierre-Yves Bourgeois 2 , Yann Kersalé 2 , Enrico Rubiola 2 and Vincent Giordano 1,2 1) ULISS-ST Business Unit, FEMTO-ST/UFC, Besancon, France 2) FEMTO-ST Institute, Time and Frequency Dept., Besancon, France Outline • Review of the CSO at Femto-ST • The ELISA project • The ULISS project • ULISS validation and preliminary tests The ULISS project is funded by:

2 Need for high short-term stability � 12 10 Cs X � tal � 13 10 ULE Metrology for industry. � ( � ) demonstrated � 14 10 y with LHe CSO CSO Space navigation since end of 90’s Primary metrology � 15 10 AHM Fundamental physics � 16 10 0.1 1 10 100 1000 10000 100000 Integration Time (s) Some applications in remote sites (Deep Space Network Antenna) Challenge: reliable cryogenerator – let alone the L-He bath

3 Cryogenic sapphire oscillator at FEMTO-ST 1995 2000 2005 2010 L He Room T and 77K 4K Cryocoolers ELISA project ULISS Project A new CSO in a small van to visit Europe Ultra-high frequency stability � 13 10 Fe3+ maser effect in WG mode sapphire � ( � ) � 14 10 y Low phase noise Osc. resonator � 15 7,5x10 5 GHz, 10 GHz, 26 GHz 32 GHz 10 � 15 10 100 1000 10000 100000 Thermal stabilisation 12 GHz Integration time (s) � Thermal compensation � 54.5dBm (deliectric thin films 10 dB deposition) 1kHz .... 12.038,135 GHz

4 ELISA project – CSO for the European Space Agency Target 3x10 -15 ADEV 1s< t <1000s, without LHe bath - Specially designed PT Cryocooler -10 GHz Resonator design (to avoid complex synthesis) Cold head � 12 10 Top flange 2010 Optical low thermal Cavity conductance � 13 10 70K stage supporting rods X � tal LHe � CSO � ( � ) UWA copper � 14 10 4K stage braids cryocooled CSO y Temperature stabilised plate Gold plated cavity ELISA � 15 10 � 16 10 0.1 1 10 100 1000 10000 100000 Integration Time (s) Demonstration of a reliable CSO suitable to remote-site installation S. Grop et al., Rev. Sci. Inst. 81, 025102 (2010) S. Grop et al., Electronics Lett., 46(6) p.420–422, 8 March 2010

5 Elisa, before moving to Argentina 2-inch sapphire monocrystal

6 ELISA in Malargüe, Argentina 30 km unpaved road April 2012 see next slide

7 Elisa frequency stability H1 maser ( ∆ t) E–H1 three cornered hat ELISA H1 maser ( ∆ t) E–H2 H2 maser ( ∆ t) H1–H2 H2 maser Σ calculated Instrument background Elisa Defective air conditioning system, 2 K pp over 1 hour

Resonator design – mode and frequency Round frequency (10 GHz) too tough Our approach: 10 GHz – 7.5 MHz ± 2 MHz offset mech. tolerances –> DDS • Oversimplify the synthesizer • Over-specify the synthesizer, thanks to favorable frequency-leverage • Ready for better-than-expected resonator • Fully reproducible machine

9 Frequency synthesis Direct 9.99 GHz 10 GHz output CSO –7.5±2 MHz 10 GHz 10 GHz input outputs LP 7.5±2 MHz DC 2.5 GHz 10 GHz heterodyne x4 BP locked PLL LP 7.5±2 MHz 10 GHz DRO 48 bit DDS frequency DDS control DDS ÷4 ÷10 word offset 0.9 µHz resolution 250 MHz at 7.5±2 MHz 100 MHz 3.6 µHz at 10 GHz outputs LP 100 MHz 3.6x10 –16 HF/VHF out ÷10 distribution 5 MHz ÷20 outputs LP 5 MHz

11 Potential users - Space agencies - VLBI observatories CSO was complex, - Metrological Centers ELISA demonstrates difficult to use - Research Labs an autonomous CSO outside a lab - T&F Industry state-of-the-art ADEV without LHe bath ULISS project - Develop a new cryocooled oscillator specially designed to be transportable. - Testing it in the potential user’s sites through Europe. - Create a business unit ULISS (managed by Univ. FC) GOTEBORG EFTF 2012 April 2012 TEDDINGTON NPL Metrology Institute BRAUNSCHWEIG PTB Metrology Institute PARIS Syrte Metrology Institute WETTZELL VLBI Observatory TOULOUSE CNES BESANCON BERNE Space Agency FEMTO − ST METAS Metrology Institute www.uliss-st.com NEUCHATEL OSA Quartz Industry TURIN Since April 2012: INRIM Metrology Institute - ULISS was build and validated CEBREROS ESA − ground station Deep Space Network - Two sites already visited (Neuchâtel and Toulouse) - ULISS was in Goteborg (EFTF 2012) - ELISA installation in Malargue

12 ULISS CSO ULISS Cryogenic Sapphire Oscillator Crycooler Electronics Control 5 MHz Ultra − stable and autonomous frequency reference (CSO) 100 MHz Frequency He Compressor synthesis Synthesis 10 GHz PCO Monitoring & CSO freq. Control PCO PC 100 MHz Input ADEV measurement ELISA/ULISS � 12 10 Relative frequency stability 3 days measurement without post-processing Perturbed environment: - Technical university (ENSMM), ≥ 800 students � 13 10 - Air conditioning still not operational during measurements � 14 � ( � ) 2 units 10 � 3 hours extracted from the entire data set - Quiet environment, nighttime ELISA - Take away 3dB for two equal units � 15 10 - Λ -counter compensated: for flicker: σ Λ ( τ ) ≃ 1.3x σ y ( τ ) � ( � ) 1 unit y flicker floor: 4x10 -16 10 s < τ < 1,000 s � 16 10 1 10 100 1000 10000 100000 Integration Time (s)

13 ULISS in Neuchâtel (LTF) - Feb 2012 - After 36h warm-up (actually, cooling down) Test photonic generation of µ-wave: ULE-cavity stabilized laser + fs 5 MHz OCXO from OSA !

14 ULISS at CNES, Toulouse, April 2012 Validate the flight prototype of the PHARAO synthesizer 9.192 GHz Phase noise 100 MHz Phase Noise Phase Noise @ 100 MHz (dBrad^2/Hz) � 60 � 80 Phase Noise @ 9.2 GHz (dBrad^2/Hz) � 70 � 90 � 80 � 100 � 90 � 110 � 100 � 120 � 110 � 130 ULISS ULISS � 120 � 140 � 130 � 150 � 160 � 140 0.1 1 10 100 1000 10000 100000 0.1 1 10 100 1000 10000 100000 Fourier Frequency (Hz) Fourier Frequency (Hz)

15 Coming soon – three sapphire oscillators Planned full measurement of S φ (f) and σ ( τ ) of Uliss before and after traveling NIST scheme Our ∆ Y scheme Ref.1 Ref.1 φ X1 detector φ X1 φ 12 φ 13 DUT DUT Ref.2 Ref.3 φ X2 φ 12 φ 23 detector φ X2 φ X3 Ref.2 !

16 SUMMARY Already demonstrated ☞ state-of-the-art short term stability ☞ reliability and reproducibility ☞ suitability to remote sites / difficult logistics ☞ metrology applications Some people believe that “cryogenic sapphire is more about a lab experiment than a reliable machine” This is definitely not true The ULISS Odyssey will continue New travels planned soon Suggestions are welcome http://uliss-st.com