Fibre pair photon sources for quantum information

This study deals with photonic crystal fiber designed to have a zero dispersion wavelength, lambda₀ close to 715 nm. A picosecond titanium-sapphire laser pumps the fibre to produce single mode pair-photons at 583 nm signal and 900 nm idler wavelength. The pairs can be collected and detected with lumped efficiencies through 10 nm interference filters up to 24% in the signal channel and 14% in the idler channel. The brightness required for multiphoton experiments can be reached with only milliwatts of pump power. This paper reports on the progress of a fibre heralded source of 1550 nm single photons relevant for quantum cryptography.