Preparation of the Quantum Correlated Optical-Terahertz Biphotons

Abstract

We study the conditions necessary for generating non-classical optical-terahertz biphotons by means of spontaneous parametric down-conversion. Using a hot electron bolometer we demonstrate detection of the THz-frequency idler waves generated under parametric up- and down-conversion with a record low gain. Complete disappearance of the classical contribution has been observed at low temperatures. A second-order biphoton correlation function is analyzed.