Sorting Single-Photon Schmidt Modes with Mode-Selective Quantum Frequency Conversio

A single photon is the natural choice of information carrier for many quantum computation and communication applications, as it interacts weakly with the environment and therefore is capable of distributing information over long distances through optical communication channels. Thus tools for efficient manipulation of photon wavelength and waveform are essential for interfacing disparate communication nodes with each other. They can also enable high-dimensional coding of information into the temporal modes. Besides single-photon wavelength translation with quantum frequency conversion (QFC), waveform manipulation through nonlinear optical processes or direct amplitude-phase modulation has attracted much recent research interest. Here we present a tool named mode-selective QFC that is facilitated by a coherent pump synthesized with optical arbitrary waveform generation (OAWG) technology. The tool can be used for mode-resolved photon counting. In combination with time-energy correlation between twin photons, such a tool can also be applied for remote manipulation of single-photon waveforms, or for generating single photons with higher production rate, compared with passive spectral filtering.;In this thesis, we will implement mode-selective QFC on single photons. A fiber-based multichannel photon-pair source in telecommunication O-band is first built as the photon source. We then demonstrate the ability to sort out the single-photon Schmidt modes through mode-selective QFC experimentally. The mode selectivity is tested by coincidence measurements of frequency-converted photons. We further theoretically investigate the advantage of incorporating mode-selective QFC in a heralded single-photon source, and the Hong-Ou-Mandel interference between multimode photons. The theoretical study shows the limitations of the current experiment, and allows for optimizing the experimental conditions to demonstrate the actual potential of the tool presented. This research work constitutes a step towards arbitrary photon-waveform manipulation.