Eur. Phys. J. D 33, 137-147 (2005)
https://doi.org/10.1140/epjd/e2005-00030-0

One-photon and two-photon double-slit interference in spontaneous and stimulated parametric down-conversions

¹ Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, P.R. China
² CCAST (World Laboratory), P.O. Box 8730, Beijing 100080, P.R. China

Corresponding author: ^a wangkg@bnu.edu.cn

Received: 27 July 2004
Revised: 17 November 2004
Published online: 1 March 2005

Abstract

We theoretically discuss two-photon double-slit interference for spontaneous and stimulated parametric down-conversions and compare it with one-photon case. We show that two-photon sub-wavelength interference can exist in a general interaction of spontaneous parametric down-conversion (SPDC) for both type I and type II crystals. In low gain SPDC, interference effect can be attributed to the previous study based on two-photon entangled state. But the important fact is that the sub-wavelength interference will not be washed out even if in very high gain SPDC, revealing the macroscopic nature. We propose an alternative scheme to observe sub-wavelength interference with a joint-intensity measurement, which occurs for a type I crystal in the high gain case. The theoretical analysis shows that the effect originates from classical thermal correlation. However, we also formulate the one-photon and two-photon double-slit interference in the stimulated process, and show amplified interference patterns.