Popis: |
Quantum illumination utilizing two-mode squeezed light beams is a promising target detection technology. It is expected that the error probability of target detection will be improved even under atmospheric disturbance such as loss and noise because of the non-classical property of the light source. One of the entangled beam, called the signal beam, is reflected by a target in atmospheric disturbance and then detected by homodyne measurement at the receiver. To improve detection efficiency, it is important to study optical wave propagation at various atmospheric conditions. We focused on fog as an example of atmospheric disturbance and investigated the effect of fog on near-infrared laser beam. We studied beam propagation using Mach-Zehnder interferometer including a chamber filled with a uniform fog. It was observed that the visibility of interference decreased with increasing fog density. Our experimental results and theoretical analysis indicate that the effect of uniform fog is mainly energy loss and does not change the spatial modes of light wave. |