Researchers demonstrate electo-optic modulation of single photons from a quantum dot

(PhysOrg.com) -- In a recent article in Applied Physics Letters, CNST researchers demonstrated how commercially available electro-optic modulators can be used to tailor the single photon output of quantum dots (QDs) for use in broadband quantum memories and other systems.

Nanoscale light-emitters such as semiconductor QDs are leading candidates for the stable generation of single photons "on demand" for use in communications, information processing, and metrology.

To create such photons, a train of can be used to optically excite a single, epitaxially-grown semiconductor QD, which then emits a train of single photon pulses. However, the temporal profile of these single photon pulses, described as a photon wave packet, is typically not ideal for use in .

Using commercial, high-performance telecommunications electro-optic modulators, the researchers were able to temporally manipulate these to produce a variety of shapes, including optimally-shaped Gaussian pulses. Compared to previous work, this approach reduced the modulation timescale more than two orders of magnitude, reaching the sub-nanosecond regime needed for semiconductor QDs.

Finally, the researchers proposed that such electro-optic modulation may be a method for improving the quality of single photons from existing QD sources. Because of decoherence, single generated by a QD are not identical, and instead have different wave packets. Electro-optic modulation could be a flexible and spectrally broadband way to select for the decoherence-free portion of the QD emission, and thereby improve the photon indistinguishability needed for quantum information processing applications.

More information: Subnanosecond electro-optic modulation of triggered single photons from a quantum dot, M. T. Rakher and K. Srinivasan, Applied Physics Letters 98, 211103 (2011). doi:10.1063/1.3593007

Abstract
Control of single photon wave-packets is an important resource for developing hybrid quantum systems which are composed of different physical systems interacting via photons. Here, we extend this control to triggered photons emitted by a quantum dot, temporally shaping single photon wave-packets on timescales fast compared to their radiative decay by electro-optic modulation. In particular, telecommunications-band single photons resulting from the recombination of an exciton in a quantum dot with exponentially decaying wave-packets are synchronously modulated to create Gaussian-shaped single photon wave-packets. We explore other pulse shapes and investigate the feasibility of this technique for increasing the indistinguishability of quantum dot generated single photons.

Citation: Researchers demonstrate electo-optic modulation of single photons from a quantum dot (2011, June 30) retrieved 28 March 2024 from https://phys.org/news/2011-06-electo-optic-modulation-photons-quantum-dot.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

World's shortest single photon pulse created

0 shares

Feedback to editors