The Hong-Ou-Mandel interferometer: A new procedure for alignment

Abstract

Two major requirements in the construction of the Hong-Ou-Mandel interferometer are the alignment and length balancing of two optical paths. A new method is presented for meeting these requirements that requires no custom optics or expensive equipment. Using this method, a two photon interferometer sourced by degenerate noncollinear parametric photon pairs was aligned and the optical paths were balanced to within an average of 11.6 μm, yielding two-photon interference features with visibilities of ∼0.9. The method is applicable to arbitrary noncollinear emission angles, including nondegenerate downconversion situations where the signal and idler emission angles differ. © 2009 American Institute of Physics.