Interference of two intersecting Bessel beams and application to laser Doppler velocimetry.

We study the interference of two intersecting similar Bessel beams. The front waves of the two beams interfere to form a distinct pattern of parallel fringes superimposed on the circular concentric fringes of the Bessel beams. We show that the two sets of fringes at the intersection region can be used in a simple laser Doppler velocimetry system to measure two velocity components. Simulations and measurements are presented to characterize the fringes and prove the concept of two-component measurement.