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Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
An optical modulator based on a single strongly coupled quantum dot--cavity system in a p-i-n junction
Dirk Englund1, Andrei Faraon, Arka Majumdar
1Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
Optics Express
|April 8, 2010
Summary
We developed a novel optical modulator using a single quantum dot and a photonic crystal cavity. This device achieves fast modulation speeds, promising high-bandwidth, low-power optical communication.
Area of Science:
- Quantum optics
- Nanophotonics
- Semiconductor devices
Background:
- Optical modulators are crucial for high-speed data transmission.
- Existing modulators face limitations in speed and power consumption.
- Quantum dots offer unique optical properties for device applications.
Purpose of the Study:
- To demonstrate a new optical modulator design utilizing a single quantum dot.
- To investigate the modulation capabilities of a quantum dot-cavity system.
- To assess the performance metrics, such as response time and potential power efficiency.
Main Methods:
- Fabrication of a vertical p-i-n junction integrated with a single quantum dot.
- Strong coupling of the quantum dot to a photonic crystal cavity.
- Characterization of cavity transmission modulation via electrical tuning of the quantum dot.
Main Results:
- Successful demonstration of an optical modulator based on a single quantum dot strongly coupled to a photonic crystal cavity.
- Measured instrument-limited response time of 13 nanoseconds.
- Tuning of quantum dot emission via the p-i-n junction to modulate cavity transmission.
Conclusions:
- A single quantum dot-based optical modulator is feasible and demonstrated.
- The device shows potential for high-bandwidth and low-power optical modulation.
- This approach offers a promising pathway for next-generation optical communication technologies.
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In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
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