80 research outputs found
Efficient long distance quantum communication
Despite the tremendous progress of quantum cryptography, efficient quantum
communication over long distances (>1000km) remains an outstanding challenge
due to fiber attenuation and operation errors accumulated over the entire
communication distance. Quantum repeaters, as a promising approach, can
overcome both photon loss and operation errors, and hence significantly speedup
the communication rate. Depending on the methods used to correct loss and
operation errors, all the proposed QR schemes can be classified into three
categories (generations). Here we present the first systematic comparison of
three generations of quantum repeaters by evaluating the cost of both temporal
and physical resources, and identify the optimized quantum repeater
architecture for a given set of experimental parameters. Our work provides a
roadmap for the experimental realizations of highly efficient quantum networks
over transcontinental distances.Comment: Sreraman Muralidharan and Linshu Li contributed equally to this wor
Multiplexed broadband beam steering system utilizing high speed MEMS mirrors
We present a beam steering system based on micro-electromechanical systems
technology that features high speed steering of multiple laser beams over a
broad wavelength range. By utilizing high speed micromirrors with a broadband
metallic coating, our system has the flexibility to simultaneously incorporate
a wide range of wavelengths and multiple beams. We demonstrate reconfiguration
of two independent beams at different wavelengths (780 and 635 nm) across a
common 5x5 array with 4 us settling time. Full simulation of the optical system
provides insights on the scalability of the system. Such a system can provide a
versatile tool for applications where fast laser multiplexing is necessary.Comment: 11 pages, 6 figures, submitte
Multi-scale Optics for Enhanced Light Collection from a Point Source
High efficiency collection of photons emitted by a point source over a wide
field-of-view (FoV) is crucial for many applications. Multi-scale optics over
improved light collection by utilizing small optical components placed close to
the optical source, while maintaining a wide FoV provided by conventional
imaging optics. In this work, we demonstrate collection efficiency of 26% of
photons emitted by a point-like source using a micromirror fabricated in
silicon with no significant decrease in collection efficiency over a 10 mm
object space.Comment: 4 pages, 4 figure
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