This experiment investigates properties of light at the single photon level. We generate pairs of 915.8-nm photons through parametric downconversion by sending a beam of 457.9-nm light through a BBO crystal. These downconverted photons are detected using two avalanche photodiodes. We then create a distinguishable characteristic in one arm of a Mach-Zehnder interferometer by adding a half wavepl...

We propose a new method for the simultaneous interrogation of conventional two-beam interferometers and Bragg grating sensors. The technique employs an unbalanced Mach-Zehnder interferometer illuminated by a single low-coherence source, which acts as a wavelength-tunable source for the grating and as a path-matched f ilter for the Fizeau interferometer, thus providing a high phase resolution ou...

Sang-Su Lee et al. 373 This paper presents a new method for a visual cryptography scheme that uses phase masks and an interferometer. To encrypt a binary image, we divided it into an arbitrary number of slides and encrypted them using an XOR process with a random key or keys. The phase mask for each encrypted image was fabricated under the proposed phase-assignment rule. For decryption, phase m...

Determination of the path taken by a quantum particle leads to a suppression of interference and to a classical behavior. We employ here a quantum "which path" detector to perform accurate path determination in a two-path Mach-Zehnder electron interferometer, leading to full suppression of the interference. Following the dephasing process we recover the interference by measuring the cross corre...

An in-fiber Mach-Zehnder interferometer (MZI) for high temperature measurement is proposed and experimentally demonstrated. The device is constructed of a piece of thin-core fiber (TCF) sandwiched between two short sections of multimode fiber (MMF), i.e., a MMF-TCF-MMF structure. A well-defined interference spectrum is obtained owing to the core-mismatch, and the interference dips are sensitive...

We propose a single-particle Mach-Zehnder interferometer experiment in which the path length of one arm can change before each passage of a particle through the interferometer. We demonstrate that this experiment can be used to determine to which extent quantum theory provides a description of the observed detection events that goes beyond statistical averages or to refute a corpuscular model (...