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Linear and nonlinear optical spectroscopy of a strongly coupled microdisk-quantum dot system
Kartik Srinivasan1, Oskar Painter
1Center for the Physics of Information, California Institute of Technology, Pasadena, California 91125, USA.
Nature
|December 8, 2007
Summary
Researchers demonstrate strong quantum coupling in a microdisk-quantum dot system using fiber optic spectroscopy. This method allows direct optical excitation, enabling efficient single photon sources and quantum studies.
Area of Science:
- Quantum optics
- Cavity quantum electrodynamics
- Solid-state physics
Background:
- Cavity quantum electrodynamics (cQED) studies quantum interactions within resonators, crucial for quantum mechanics and information processing.
- Semiconductor quantum dots in microdisks are a scalable platform for cQED, complementing traditional alkali atom systems.
- Previous research focused on photoluminescence, limiting direct optical interaction with the quantum dot.
Purpose of the Study:
- To demonstrate direct optical spectroscopy of a quantum dot-microdisk system using a fiber taper waveguide.
- To achieve and verify strong coupling in this system via vacuum Rabi splitting.
- To investigate the nonlinear optical properties of the cavity-quantum dot system.
Main Methods:
- Utilizing a fiber taper waveguide for direct optical excitation of the quantum dot-microdisk system.
- Performing optical spectroscopy by analyzing transmitted and reflected signals from the cavity.
- Observing vacuum Rabi splitting to confirm strong coupling.
Main Results:
- Demonstrated strong coupling between the quantum dot and the microdisk cavity, evidenced by vacuum Rabi splitting.
- Achieved direct optical excitation and spectroscopy through the fiber taper waveguide.
- Observed saturation of the cavity-quantum dot response at less than one intracavity photon, indicating nonlinear properties.
Conclusions:
- Fiber optic excitation provides a direct pathway for studying quantum dot-microdisk systems.
- This approach facilitates the development of high-efficiency single photon sources.
- The method is valuable for fundamental investigations into the quantum nature of these systems.
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