Abstract: Techniques for converting signal and idler photons generated by a nonlinear optical system into a deterministic stream of single photons including receiving a heralded, nondeterministic source of signal and idler photons from the nonlinear optical process, separating one or more received signal photons from one or more received temporally corresponding idler photons, determining whether at least one of the one or more signal photons should be variably delayed, and if so, determining a delay length, and variably delaying the emission of one of the one or more signal photons, if any, by the determined delay length.

Abstract: A method for distributing a quantum key is provided, including sending a first photon to a first receiver; sending a second photon to a second receiver, the first and second photons being a pair of time-energy entangled photons; and providing a coding scheme comprising a plurality of time bins and a plurality of frequency bins, wherein a combination of a time bin and a frequency bin corresponds to a character.

Abstract: Systems for untethered sensing and recording of activity of one or more electrically excitable cells in a target region includes at least one untethered probe. Each untethered probe includes at least one signal detector, configured to electrically couple to the target region, measure the activity of the one or more electrically excitable cells, and produce an electrical signal in response to the activity of the one or more electrically excitable cells, and at least one light source, electrically coupled to the at least one signal detector, to receive the electrical signal and emit a light signal representing the activity of the one or more electrically excitable cells. Methods for untethered sensing and recording of activity of one or more electrically excitable cells in a target region are also provided.

Abstract: Techniques for fabricating thin single crystal diamond films from a diamond structure having a top surface including implanting a dose of ions at a predetermined depth below the top surface to form a damage layer, selectively masking the top surface to expose one or more portions of the diamond structure, vertically etching one or more of the exposed portions to the predetermined depth, and exfoliating the unexposed portion to form at least one thin single crystal diamond film.