Publications

Speckle size considerations for ESPI and Doppler applications

Reu, Phillip L.; Hansche, Bruce D.; Massad, Jordan M.

Contrary to popular opinion, fully resolved speckles may not be the best option for interferometric applications where it is often advantageous to have unresolved speckles with up to hundreds of speckles in a single camera pixel. This paper seeks to elucidate the effect of unresolved speckles on electronic speckle pattern interferometry (ESPI) and laser Doppler velocimetry (LDV). Related techniques such as temporal speckle pattern interferometry (TSPI) and ultrasonic imaging can also benefit from the ideas presented in this paper. Speckle statistics will be briefly outlined as background to the main topic of optimizing speckle fields for use in interferometry. The complementary speckle-size analysis for LDV is compared to previous published results on ESPI.