Citation
Abstract
We address the problem of selecting an optimum field of view (FOV) for an optical communications link. We derive a closed-form equation that provides an approximation to the optimum FOV as a function of an incident signal-to-noise-ratio (SNR) and the signal i spot intensity variance. Using this expression, we show that in the limit of small SNR one i wants to encircle 72 percent of the signal power. The optimum fraction is increasing with SNR, so it follows that one always wants to encircle at least 72 percent of the signal. We i provide an expression for the loss in selecting a suboptimal FOV and find the FOV that we conjecture minimizes the maximum loss. This FOV corresponds to encircling 91 percent of the signal power and limits the maximum loss to less than 0.4 dB in signal power for a target capacity. Finally, we illustrate an application of using the estimate to select an optimum FOV for a pixellated focal plane illuminated by a speckled signal intensity pattern.
Details
- Volume
- 42-190
- Published
- August 15, 2012
- Pages
- 1–12
- File Size
- 629.3 KB