Thorlabs' Correlated Photon-Pair Source uses spontaneous parametric down-conversion (SPDC) to create a pair of energy-time entangled photons at 810 nm. With an integrated 405 nm pump laser, this self-contained source results in >450k photon pairs per second and a high-efficiency heralding ratio of >0.45.
A zero-time delay second-order correlation function [g(2) (τ = 0)] value of <0.1 can be achieved with this source, making it a high-brightness heralded single-photon source ideal for quantum optics applications.
Photon-Pair Source shown with the P1-780PM-FC-1 patch cables (included) connected to the signal and idler outputs. The provided 12 V power supply and RS232 cable (not included) are also connected.
- Heralded Single-Photon Source with g(2)(τ = 0) < 0.1
- Spontaneous Parametric Down-Conversion (SPDC) Source
(Collinear Type-II) - Photon-Pair Generation at 810 nm
- Integrated 405 nm Pump Laser
- >0.45 High-Efficiency Heralding Ratio
- >450 kHz Pair Generation Rate
- ±2.5 nm Wavelength Stability for Emitted Photons
- Room Temperature Operation
Collinear Type-II SPDC of one 405 nm pump photon entering a PPKTP crystal and exiting as two 810 nm output photons.
In this SPDC source, a nonlinear crystal [periodically poled potassium titanyl phosphate (PPKTP)] converts one 405 nm pump photon into two 810 nm photons (the signal and idler) in a single event. The resulting signal and idler photons have type-II phase matching, which means they propagate with orthogonal polarizations (extraordinary and ordinary); see the schematics to the right. As a source that emits photon-pairs in a simultaneous event, it can be used as a heralded single-photon source. This is when the detection of one photon (idler) heralds the presence of the second photon (signal).
A second-order correlation measurement [g(2)(τ)] between signal and idler photons. The peak at τ = 0 confirms the generation of photon pairs.