Researchers from the National Institute of Standards and Technology (NIST), the University of California, San Diego; and the Politecnico di Milano in Milan, Italy, have demonstrated the first “heralded” single photon source made from silicon in what the team is calling an important step towards more practical quantum information processing. The associated academic paper was published in the AIP’s open access journal Applied Physics Letters, published on June 25 2012.

This novel source complements two other recently developed silicon-based technologies — interferometers for manipulating the entanglement of photons and single photon detectors, which are needed to build a quantum optical circuit or a secure quantum communication system.

The line between “interesting” and practical in advanced electronics and optics often comes down to making the new device compatible with existing technology. According to NIST scientist Kartik Srinivasan, the new 0.5 mm x 0.05 mm-sized heralded photongenerator meshes with existing technology in three important ways: it operates at room temperature; it produces photons compatible with existing telecommunications systems (wavelengths of about 1550 nm); and it is formed in silicon, and so can be built using standard, scalable fabrication techniques.

Two of a kind: Photon pair generation, in which input pump photons spontaneously create pairs of photons.

To read more: http://optics.org/news/3/7/9