Defense (1)

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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