The Performance of Chip-Scale Atomic Clocks V. Gerginov 1, S. Knappe 2, P.D.D. Schwindt 3, V. Shah...
-
date post
22-Dec-2015 -
Category
Documents
-
view
216 -
download
0
Transcript of The Performance of Chip-Scale Atomic Clocks V. Gerginov 1, S. Knappe 2, P.D.D. Schwindt 3, V. Shah...
The Performance of Chip-Scale Atomic Clocks
V. Gerginov1, S. Knappe2, P.D.D. Schwindt3, V. Shah2, J. Kitching3, L. Hollberg3
In collaboration with:
J. Moreland4, L. Liew4, S. Song4
Z. Popovic2, A. Brannon2
1Also with University of Notre Dame, Notre Dame, IN 465562Also with University of Colorado, Boulder, CO 80309
3National Institute of Standards and Technology, Boulder, CO 80305
4Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305
PrimaryStandard
CompactAtomic Clock
Loses 1 sec. in: 108 years 1000 years Size: 107 cm3 100 cm3 Power: kW 5 W Cost: $1 M $1,000
Higher Precision
Smaller Size
???
CSAC
1000 years 1cm3
30 mW$100
WristwatchQuartz Crystal
PrecisionQuartz Crystal
1 year 1 day1 cm3 10-3 cm3
30 mW 10 W$100 $1
Types of clocks
CPT-Based Chip-Scale Atomic Clock
Arimondo et al., Lett. Nuovo Cim., 17, 333, 1976 Alzetta et al., Il Nuovo Cim. 36B, 5, 1976Bell et al., Phys. Rev. Lett. 6, 280, 1961
1 2
12
2RF= 1- 2= 12
12
RF
Clock Assembly
Micromachined Vapor Cell Atomic ClockJ. Kitching, S. Knappe and L. Hollberg, Appl. Phys. Lett., 81, 553, 2002S. Knappe, L. Liew, V. Shah, P. Schwindt, J. Moreland, L. Hollberg and J. Kitching, Appl. Phys. Lett. 85, 1460, 2004
CSAC V
Local Oscillator
Alla
n de
viat
ion
Power Consumption5 mW DC at 1.6V
Phase Noise -92dBc / Hz @ 10kHz offset -33dBc / Hz @ 100Hz offset
RF Output Power -6dBm to -9dBm @ 3.417 GHz
Thermal drift 0ppm / K at room temperature -17ppm / K avg. over 0 ºC to 50 ºC the range
Tuning Range3 MHz
Size0.49 cm2
LO locked to table-top experiment
LO locked to CSAC V
A. Brannon et al., 2005 IEEE MTT-S Int. Microwave Symp Dig.
Clock PerformanceParameter Power Comment
Laser electrical
2.5mW Current 1.8mA
Laser heating 55mW (45mW1) Temp. 80oC
Cell heating 68mW (24mW1) Temp 85oC
Magn. field <0.1mW
RF modulation 0.6mW -2.5dBm
Total 126mW (72mW)
1in vacuum
Limitations on long-term stability:- environment temp. changes- laser parameter changes - CPT resonance drift
Components OptimizationCell performance (table top experiment)
Cell dimensions 1x1x1mmBuffer gas Ar-Ne mixtureCPT linewidth 1.2kHz @ 3% contrast (ratio CPT amplitude to optical absorption)
S. Knappe et al., submitted to Optics Letters
Laser Performance (table top experiment)
Local Oscillator Performance (table top experiment)
Conclusions
1. Atomic clock (physics package <1cm3 ) operating below 100 mW
2. Local oscillator consuming 5mW locked to the physics package
3. Demonstrated 1mm3 87Rb vapor cell with reduced clock frequency drifts
4. Reduced clock sensitivity to laser temperature and LO power changes