Single-photon statistics generated by narrow-band cavity-enhanced parametric down-conversion

T. B. Pittman, B. C. Jacobs, J. D. Franson

Matthias Scholz, Lars Koch, Oliver J. Benson

We present a single-photon source based on cavity-enhanced parametric down-conversion with < 3 MHz linewidth and a brightness of 14000 counts/(s×mW×MHz). Measuring heralded single-photon statistics, we achieved a 100-fold suppression of two-photon events compared to a Poissonian source.

Matthias Scholz, Lars Koch, Oliver J. Benson

Narrow-band single photons represent an important resource for quantum memories due to their efficient interaction with atomic resonances. In this Letter, we report on the generation of photons with 3 MHz linewidth by cavity-enhanced parametric down-conversion and demonstrate direct proof of their single-photon character by detection of heralding idler photons. Compared to a Poissonian source, a suppression of higher-order photon numbers by nearly 2 orders of magnitude could be achieved. Moreover, the brightness of our source exceeds previous realizations by more than a factor of 100.

Barry C. Sanders, Edo Waks A, Eleni Diamanti +1 more

Lars Koch, Matthias Scholz, Oliver J. Benson

This paper presents an experiment on single-photon spectrum generation using an optical parametric oscillator device with cavity-enhanced parametric down-conversion. A PPKTP crystal inside a cavity far below threshold is pumped in order to create signal-idler photon pairs. Triple-resonance of pump, signal, and idler fields are achieved using a compensating KTP crystal. Long-term stability, ultra-high brightness (14000 biphotons/s per mW), and MHz signal bandwidth behind a single-mode fiber on the cesium D1 line (894.3 nm) are attained by locking the cavity length of the pump via the Hansch-Couillaud method. The spectral width of the parametric fluorescence is also derived using the signal-to-idler cross-correlation measurements, and has been found to be < 3 MHz.

Preston Alexander, Scott Baldwin, S. Blane McCracken +1 more