May 2017
Spotlight Summary by Peter J. Mosley
Pulsed single-photon spectrometer by frequency-to-time mapping using chirped fiber Bragg gratings
Precise and rapid measurement of single-photon spectra is critical to photonic quantum-enhanced technologies. Exploiting the frequency-time structure of single photons could be of huge benefit in current efforts to develop new capabilities in the fields of communication, computation, and sensing, for example by enabling greater information-carrying capacity per photon. On the other hand, random fluctuations in frequency degrade interference in quantum logic gates and prevent the assembly of large-scale entangled states. Whichever way you look at it, the spectra of single photons must be well-characterized in order to be controlled.
The authors present a new method of measuring the frequency structure of single photons through using group-velocity dispersion to map frequency to time. At telecoms wavelengths this can be done with low loss in fiber, but here the authors were working around 800 nm, where fiber attenuation is too high to provide sufficient cumulative dispersion. Instead, they used a chirped fiber Bragg grating spliced to a circulator to create a device with large group delay dispersion between 825–835 nm. Hence, they were able to characterize in detail the spectra of photon-pairs from parametric downconversion, as well as monitoring many frequency channels simultaneously. The technique is likely to find use in time-frequency quantum communications and optical quantum state engineering.
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The authors present a new method of measuring the frequency structure of single photons through using group-velocity dispersion to map frequency to time. At telecoms wavelengths this can be done with low loss in fiber, but here the authors were working around 800 nm, where fiber attenuation is too high to provide sufficient cumulative dispersion. Instead, they used a chirped fiber Bragg grating spliced to a circulator to create a device with large group delay dispersion between 825–835 nm. Hence, they were able to characterize in detail the spectra of photon-pairs from parametric downconversion, as well as monitoring many frequency channels simultaneously. The technique is likely to find use in time-frequency quantum communications and optical quantum state engineering.
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Article Information
Pulsed single-photon spectrometer by frequency-to-time mapping using chirped fiber Bragg gratings
Alex O. C. Davis, Paul M. Saulnier, Michał Karpiński, and Brian J. Smith
Opt. Express 25(11) 12804-12811 (2017) View: Abstract | HTML | PDF