Two-component LDA using optical multiplexing

The use of a Y-fed balanced bridge modulator is suggested as a means to realize optical multiplexing in a dual beam laser Doppler anemometer. The resulting system measures two components of velocity but uses only one laser source, one photodetector and one signal processing electronic system. In this paper a laboratory system is described and verification experiments to investigate the performance of the system are presented. Finally, suggestions are made for improving the system.