Comparative study with double-exposure digital holographic interferometry and a shack-hartmann sensor to characterize transparent materials.

We compare wave-front measurements using double-exposure digital holography and a Shack-Hartmann sensor. A voltage-driven liquid-crystal wedge modulates the optical wave front and provides a refractive-index gradient typical of interesting transparent materials. Measurement accuracy and reliability are similar for both methods.

Microgravity materials and life sciences research applications of digital holography.

We investigate the utility of digital holographic interferometry for analyzing gravity-dependent mass transport phenomena as applicable to materials and life science research topics. Digital holography is useful for measurement of parameters that introduce phase changes in light traversing the material of interest, such as temperature or concentration variations in an aqueous environment. We have constructed, tested, and verified a compact, portable digital holographic monitor (DHM) suitable for characterization of transparent samples.