Precise information about the temporal mode of optical states is crucial for optimizing their interaction efficiency between themselves and/or with matter in various quantum communication devices. Here we propose and experimentally demonstrate a meth
od of determining both the real and imaginary components of a single photons temporal density matrix by measuring the autocorrelation function of the photocurrent from a balanced homodyne detector at multiple local oscillator frequencies. We test our method on single photons heralded from biphotons generated via four-wave mixing in an atomic vapor and obtain excellent agreement with theoretical predictions for several settings.
A system using a personal computer, speaker, and a microphone is used to detect objects, and make crude measurements using a carrier modulated by a pseudorandom noise (PN) code. This system can be constructed using a personal computer and audio equip
ment commonly found in the laboratory or at home, or more sophisticated equipment that can be purchased at reasonable cost. We demonstrate its value as an instructional tool for teaching concepts of remote sensing and digital signal processing.
Copper ferrite thin films were rf sputtered at a power of 50W. The as deposited films were annealed in air at 800{deg}C and slow cooled. The transmission electron microscope (TEM) studies were carried out on as deposited as well as on slow cooled fil
m. Significantly larger defect concentration, including stacking faults, was observed in 50W as deposited films than the films deposited at a higher rf power of 200W. The film annealed at 800{deg}C and then slow cooled showed an unusual grain growth upto 180nm for a film thickness of ~240nm. These grains showed Kikuchi pattern.
