Abstract
We demonstrate a miniature source of long biphotons utilizing the cluster effect and double-pass pumping in a monolithic doubly resonant parametric down-converter. We obtain a biphoton correlation time of 17.1 ns with a generation rate of 1.10 × 10 5 biphotons/(s mW) and an estimated linewidth of 8.3 MHz. © 2012 American Institute of Physics.