Scott E. Spence

Methods used to observe a dynamical quantum nonlocality effect in a twin Mach–Zehnder interferometer

Straightforward novel methods for stabilizing, tuning, and controlling a twin Mach-Zehnder interferometer for the purpose of observing a subtle dynamical quantum nonlocality effect in a recent optical experiment are presented and discussed. Weak measurements were required for observing a subtle quantum dynamical nonlocality effect that reveals itself in a change of a weak value. Consequently, emphasis is placed upon describing the approaches to apparatus stabilization and interaction strength control between photons and the apparatus. The details discussed in this paper should be of general interest to experimentalists engaging in weak measurement and weak value research.

Weak value amplification of an off-resonance Goos-Hänchen shift in a Kretschmann-Raether surface plasmon resonance device.

During the past two decades there has been increased interest in the optical excitation of surface plasmon resonance (SPR) at a metal-dielectric interface. This is due in large part to its potential applications in such areas as medical diagnostics and pharmaceutical research. Also occurring during this time has been a growing recognition by the quantum physics community that weak value amplification (WVA) can serve as a valuable metrological research resource. Recently WVA has been used to amplify very small optical Goos-Hänchen (GH) shifts in glass and it has also been shown that SPR can greatly enhance optical GH shifts at the metal/air interface in Kretschmann-Raether (KR) devices. This paper demonstrates experimentally the WVA of an off-resonance GH shift in a KR device and explains why WVA of sufficiently SPR enhanced optical GH shifts cannot be achieved.

Weak value amplification of an optical Faraday differential refraction effect

In the presence of a longitudinal magnetic field B, a beam of linearly polarized light incident from a Faraday medium of Verdet constant V refracts at its interface with a medium of negligible Verdet constant and emerges as two opposite circularly polarized beams that are separated by a small divergence angle δ that is proportional to the product BV. Judicious postselection of the polarization state of the emergent light can be used to amplify the measured value of δ by several orders of magnitude. This technique makes it possible to optically measure either very small V values when B is known or small magnetic fields when V is known.

The Development Of Steady State Modal Conditions In Short Length Concatenated Systems

The development of steady state modal conditions in several short length concatenations was studied. The resultant steady state distribution was identified as approximately equivalent to a 70/100 beam optics launch into a short reference fiber. Mechanical methods of reproducing the distribution in a short length of fiber with an initial overfill condition were also studied.

Capacity and Entropy of a Retro-Causal Channel Observed in a Twin Mach-Zehnder Interferometer During Measurements of Pre- and Post-Selected Quantum Systems

Simple intuitive models are presented for the capacity and entropy of retro-causal channels in measured ensembles of quantum systems which can be represented as statistical mixtures of pre-selected only and pre- and post-selected systems. Measurement data from a twin Mach-Zehnder interferometer experiment are used in these models to discuss the capacity and entropy of an apparent retro-causal channel observed in the experimental data. It is noted that low capacity/low entropy retro-causal channels can exist in strong measurement systems.

Ray tracing analysis of a two-dimensional rectangular optical cavity for enhancing detector efficiency.

High detector efficiency has broad appeal and includes such diverse fields as quantum optics and solar energy. An optical resonator can improve detector efficiency by employing multiple re-reflections to the detector. This short paper uses geometric ray tracing to examine-for a given entry port size-the probability that a photon will escape from an ideal perfectly reflective two-dimensional cavity.

High-impact shock testing of fiber optic components

MIL-S-901 High Impact Shock tests were performed on commercial-grade and ruggedized fiber optic connectors, splices, and switches. Both singlemode and multimode connectors and splices were tested. Only multimode switches were tested. Transient losses of varying magnitudes and durations were observed. Most components suffered no permanent degradation.

Vibration Testing Of Fiber Optic Components

Vibration tests were performed on commercial grade fiber optic connectors and splices. Both singlemode and multimode components were tested. Sinusoidal vibrations up to 500 Hz and random vibrations up to 2000 Hz were applied. Analog modulation was negligible and no permanent damage was observed.

Temperature And Humidity Testing Of Fiber Optic Components

Temperature and humidity tests were performed on commercial grade fiber optic couplers, connectors, splices and optical,fiber. Both singlemode and multimode components were tested. Temperatures ranged from -54°C to +65°C or +85°C depending on the component application. In the humidity tests the relative humidity was maintained at greater than 95 percent above 20°C. Changes in optical transmittance of varying degrees and permanent damage were observed and recorded.