Efficient generation of temporally shaped photons using nonlocal spectral filtering

TL;DR

This paper presents a method for efficiently generating single photons with tailored temporal shapes using nonlocal spectral filtering, enabling higher heralding rates and compatibility with quantum emitters.

Contribution

The authors introduce a nonlocal spectral filtering technique that shapes photon temporal profiles without post-selection, improving heralding efficiency and enabling long coherence time photon generation.

Findings

Temporal shape is defined by the time-inverted impulse response of the spectral filter.

Method achieves higher heralding rates compared to nonlocal temporal modulation.

Can produce photons with exponential rise shapes suitable for quantum interfaces.

Abstract

We study the generation of single-photon pulses with the tailored temporal shape via nonlocal spectral filtering. A shaped photon is heralded from a time-energy entangled photon pair upon spectral filtering and time-resolved detection of its entangled counterpart. We show that the temporal shape of the heralded photon is defined by the time-inverted impulse response of the spectral filter and does not depend on the heralding instant. Thus one can avoid post-selection of particular heralding instants and achieve substantially higher heralding rate of shaped photons as compared to the generation of photons via nonlocal temporal modulation. Furthermore, the method can be used to generate shaped photons with a coherence time in the ns-$\mu$s range and is particularly suitable to produce photons with the exponentially rising temporal shape required for efficient interfacing to a single quantum emitter in free space.