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 Grop1, Benoit Dubois1, Jean Louis Masson2, Gregory Haye1,2, Pierre-Yves Bourgeois2, Yann Kersalé2, Enrico Rubiola2 and Vincent Giordano1,2

1)ULISS-ST Business Unit, FEMTO-ST/UFC, Besancon, France 2) FEMTO-ST Institute, Time and Frequency Dept., Besancon, France

The ULISS project is funded by:

• Review of the CSO at Femto-ST
• The ELISA project
• The ULISS project
• ULISS validation and preliminary tests

Outline

Need for high short-term stability

Integration Time (s)

16 14 13 12

()

15 y

10 10 10 1 10 100 1000 10000 100000 0.1 10 Xtal AHM ULE Cs 10 CSO

Space navigation Metrology for industry. Fundamental physics Some applications in remote sites (Deep Space Network Antenna) Challenge: reliable cryogenerator – let alone the L-He bath Primary metrology demonstrated with LHe CSO since end of 90’s 2

Cryogenic sapphire oscillator at FEMTO-ST

1995 2000 2005 2010

32 GHz

12 GHz

Room T and 77K

Low phase noise Osc. 5 GHz, 10 GHz, 26 GHz Thermal stabilisation Thermal compensation (deliectric thin films deposition) .... Ultra-high frequency stability Fe3+ maser effect in WG mode sapphire resonator

10 10 1015

14 13

()

y

• Integration time (s)

15

10 1000 10000 100000 100 7,5x10

54.5dBm 10 dB 1kHz 12.038,135 GHz

ELISA project ULISS Project A new CSO in a small van to visit Europe

L He 4K Cryocoolers 3

ELISA project – CSO for the European Space Agency

Target 3x10-15 ADEV 1s<t<1000s, without LHe bath

conductance supporting rods copper braids Temperature stabilised plate Gold plated cavity Top flange Cold head 4K stage low thermal 70K stage

• Specially designed PT Cryocooler
• 10 GHz Resonator design (to avoid complex synthesis)

Integration Time (s)

13 15 12

()

y 16 14

10 10 10 Optical 1 10 100 1000 10000 100000 0.1 UWA Cavity ELISA Xtal LHeCSO 10 cryocooled CSO 10

2010 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

4

Elisa, before moving to Argentina

5

2-inch sapphire monocrystal

ELISA in Malargüe, Argentina April 2012

30 km unpaved road

6 see next slide

Instrument background

Elisa H1 maser H2 maser

Defective air conditioning system, 2 Kpp over 1 hour

ELISA H1 maser H2 maser (∆t)E–H1

Σ

three cornered hat (∆t)E–H2 (∆t)H1–H2

calculated

Elisa frequency stability

7

Resonator design – mode and frequency 10 GHz – 7.5 MHz ± 2 MHz

• mech. tolerances –> DDS
• ffset

Round frequency (10 GHz) too tough Our approach:

• Oversimplify the synthesizer
• Over-specify the synthesizer, thanks to favorable frequency-leverage
• Ready for better-than-expected resonator
• Fully reproducible machine

9

Frequency synthesis

10 GHz locked 7.5±2 MHz 7.5±2 MHz DC

÷20

LP

x4

BP

÷4

÷10 ÷10

LP

100 MHz

• utputs

5 MHz

• utputs

10 GHz

• utputs

Direct

• utput

CSO 9.99 GHz input

LP

2.5 GHz DRO 10 GHz

DDS

250 MHz

word DDS control

10 GHz

LP

5 MHz 100 MHz

10 GHz –7.5±2 MHz HF/VHF out distribution heterodyne PLL frequency

• ffset

48 bit DDS 0.9 µHz resolution at 7.5±2 MHz 3.6 µHz at 10 GHz 3.6x10–16

Potential users

• Space agencies
• VLBI observatories
• Metrological Centers
• Research Labs
• T&F Industry

ELISA demonstrates an autonomous CSO state-of-the-art ADEV without LHe bath CSO was complex, difficult to use

• utside a lab
• 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)

www.uliss-st.com

Since April 2012:

• ULISS was build and validated
• Two sites already visited (Neuchâtel and Toulouse)
• ULISS was in Goteborg (EFTF 2012)
• ELISA installation in Malargue

ULISS project 11

ULISS CSO

Electronics Control Synthesis PCO PC Crycooler He Compressor

Monitoring & Control 100 MHz Input CSO freq. 10 GHz 100 MHz 5 MHz Ultra−stable and autonomous frequency reference (CSO) Frequency synthesis

ULISS Cryogenic Sapphire Oscillator

PCO

Integration Time (s)

15 12 13

Relative frequency stability

14 16

10 10 10 10 10

• y

2 units () 1 unit ()

1 10 100 1000 10000 100000

ADEV measurement ELISA/ULISS

3 days measurement without post-processing Perturbed environment:

• Technical university (ENSMM), ≥ 800 students
• Air conditioning still not operational during

measurements ELISA 3 hours extracted from the entire data set

• Quiet environment, nighttime
• Take away 3dB for two equal units
• Λ-counter compensated: for flicker: σΛ(τ)≃ 1.3xσy(τ)

flicker floor: 4x10-16 10 s < τ < 1,000 s 12

ULISS in Neuchâtel (LTF) - Feb 2012 -

Test photonic generation of µ-wave: ULE-cavity stabilized laser + fs 5 MHz OCXO from OSA

!

After 36h warm-up (actually, cooling down) 13

ULISS at CNES, Toulouse, April 2012

Validate the flight prototype of the PHARAO synthesizer

Fourier Frequency (Hz) 130 120 110 100 90 80 70 60 0.1 1 10 100 1000 10000 100000 Phase Noise @ 9.2 GHz (dBrad^2/Hz) 140 Fourier Frequency (Hz) 150 140 130 120 110 100 90 80 0.1 1 10 100 1000 10000 100000 Phase Noise @ 100 MHz (dBrad^2/Hz) 160

9.192 GHz Phase noise 100 MHz Phase Noise

ULISS ULISS

14

detector

DUT

Ref.2

φX1

Ref.1 Ref.3

φ12 φ23 φ13 φX3 φX2 DUT

Ref.2 Ref.1

φ12 φX2 φX1

detector

NIST scheme Our ∆Y scheme

!

Coming soon – three sapphire oscillators

15 Planned full measurement of Sφ(f) and σ(τ) of Uliss before and after traveling

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 16

http://uliss-st.com