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TRANSCRIPT
Increasing quantum limited sensitivity of interferometers using electromagnetically
induced transparency
Hunter RewAdvised by Dr. Eugeniy Mikhailov
What to expect
● Introduction○ Gravitational wave detection○ Increasing sensitivity○ Electromagnetically induced transparency
● Simulation methods and results● Experimental methods and results● Conclusions
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Gravitational Waves
Gravitational waves (GWs) are a prediction of general relativity.
GWs contract space in one direction while expanding it in transverse directions
Copyright: [NASA]
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Interferometric Gravitational Wave Detectors
GW changes lengths of arms relative to each other, creating a phase shift in the light
GW interferometers such as Advanced LIGO are approaching the standard quantum limit
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Uncertainty and Squeezing
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Noise in LIGO
Noise sources within LIGO are frequency dependent
6[Nature Photonics 7, 613–619 (2013) doi:10.1038/nphoton.2013.177]
Electromagnetically Induced Transparency
Opaque media become transparent when optical fields are applied at the transitions of hyperfine ground states. A dark state is produced from the superposition of these states.
● Produce narrow linewidths● Near 100% transmission● Tunable
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The Lambda Model [4]
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Simulation Methods
● eXtensible Multi-Dimensional Simulator (XMDS)● SciClone
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[XMDS]
Simulated EIT (Results)
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Methods (cont.)
Simulations varied the following parameters:
● Drive Rabi frequency (Ωd) from 17 to 25 KHz● 2 photon detuning ( ) with a range based on the given drive● Time from 0 to 0.1 s● Media length from 0 to 2 cm
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Methods (cont.)
Constants:
● Probe Rabi frequency (Ωp) of 0.1 Hz● Excited state decay (γ) of 6 MHz● Ground state decay (γbc) of 1 Hz● Particle density of 1015 particles per m3
● Transitions at 794.7 nm
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Simulated EIT (Definitions)
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Data is fit to a generalized Lorentzian
A is the contrast
γ is the linewidth / 2
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Region of interest
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Experimental setup
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Experimental parameters
● Rubidium cell is roughly 1.5 cm in diameter and 1 cm in length○ Anti-relaxation coating
● Drive and probe intensities are roughly equal○ Rabi frequencies from 5 to 30 MHz
● Cell temperatures from 35 to 75 Celsius○ Particle concentrations from 3 x 1010 to 9 x 1011
● Beam waists from full to 0.8ω0
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Analysis of experimental data
Data is fit to a generalized Lorentzian
A is the contrast
γ is the linewidth / 2
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Experiment vs simulation: contrast vs drive
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Experiment vs simulation: width vs drive
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Experiment vs simulation: transmission vs concentration
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Experiment vs simulation: width vs concentration
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Experiment vs simulation: contrast vs concentration
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Varying concentration
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Reminder of experimental setup
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Varying beam size
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Conclusions and future work
● Best contrast: 3.9%● Best linewidth: 202 Hz● Experiment and simulation
agree (mostly)● Low temperatures show
promise● Low drive intensities show
promise
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Acknowledgements
● Dr. Eugeniy Mikhailov● Dr. Irina Novikova● SciClone
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