Quantum enhancements in optical imaging and sensing
The fundamental limits of photonic information processing---be it the maximum rate of reliable communications, resolution of an optical imager, or the computational power of an optical computer---are all ultimately governed by the laws of quantum mechanics. Most conventional systems, which do not exploit the manifestly quantum properties of light, are limited to classical (often purportedly fundamental) performance limits that can be far inferior to the quantum-mandated limits. In this talk, I will discuss a few simple illustrative problems in active and passive optical imaging and sensing, where exploiting quantum effects, by using quantum illumination and/or by employing non-standard all-optical pre-detection processing locally at the receiver, one can yield improved performance over a classical baseline imager that uses the same transmit power and optical bandwidth. I will discuss recent results indicative of an important role of entangled probes in distributed sensing problems. Finally, I will discuss general characteristics of imaging scenarios where quantum improvements can be expected to be had (or not), and the respective natures of enhancements in performance.