Researchers Generate Tunable Photon-Pair Spectrum using Room-Temperature Quantum Optics Silicon Chip >>found a way to emit and control quantum light generated w/ a chip made from #silicon instead of more expensive, harder-to-make compound semiconductors. These devices could have #applications in secure communications, precise measurements of motion or shape, and sensing using ultra-low levels of light. eg silicon pair-generation chip could be used as part of a more complicated #quantum #transceiver module, which would eventually integrate a controllable photon source with a sensitive photon detector in a single package. #Method of Nanophotonic Chip ~A beam of light from a #laser #diode is shone into the chip, and for each pair of photons from the input beam that is absorbed by the material, a pair of photons is produced at 2 slightly different frequencies - one higher than the input and the other lower than it, such that the total energy is conserved, ....Our chip is compact -- only millimeters in size -- and it works at #room temperature, and only requires a simple telecommunications-grade low-power laser diode as the input, and #filters to separate the two daughter photons from their parent beam. ~One thing you have to do, though, is to pattern the silicon into waveguides and micro-resonators which enhance the optical intensity at specific wavelengths, ie chip is patterned using #lithography Eg For a particular patterned structure: by varying the chip temperature by only a few degrees, we can tune the degree of entanglement by more than a factor of three, as measured by a typical metric called the Schmidt number, #NOTE; The #degree of #entanglement is related to a measurement called the Joint Spectral Intensity (#JSI), and measured using single photon detectors. JSI of the chip can be varied by tuning the temperature of the chip by a few degs, using compact thermo-electric controllers like those typically used with practical opto-electronic microchips. jacobsschool.ucsd.edu/news/news_releases/release.sfe?id=1680
Posted on: Tue, 16 Dec 2014 16:38:39 +0000
Trending Topics
Recently Viewed Topics
© 2015