Recent Progress in Multi-Channel Quadrature Interferometer: Demonstration of a Compact Fiberized Architecture

The new laser‐based ultrasonic receiver that is based on multi‐channel interferometry is shown to be well suited for robust and sensitive detection of ultrasound in industrial environment. The proposed architecture combines random quadrature detection with detector arrays for multi‐speckle processing. Two improvements are presented. First, a simple modification of the detection scheme is demonstrated for rejection of the laser intensity noise, making possible the use of lower cost laser without reduction in performances. Second, a compact fiberized architecture is demonstrated. The optical fiber is used for both generating the reference beam and creating the interference between the reference and object beams. Results demonstrating these two improvements are presented.