Optimizing image-to-background irradiance ratio in far-field in-line holography.

The role of the background irradiance in far-field in-line holography has been systematically studied for improving image-to-background intensity ratio. With given exposure limits, the allowable range for average or background exposure is also discussed for the recordability of high-contrast fringes. A specific example of an Agfa 10E75 plate is considered. Within the allowed background exposure limits, the possibilities are then discussed for optimizing the image-to-background irradiance ratio. Limits caused by the dynamic range of the video system are discussed. Some experimental results are also presented.