DEVELOPMENT OF A MULTIPOINT LDV BY USING SEMICONDUCTOR-LASER WITH FFT-BASED MULTICHANNEL SIGNAL-PROCESSING

An advanced multi-point LDV with FFT-based multi-channel signal proces sing, using a 1-bit FFT approach has been developed. A semiconductor l aser light sheet, a 96-channel plastic optical fiber array, 16-Si APDs and a 16-channel capacious (1 M word) memory system with 1 bit were u sed in order to attain 16 individual Doppler frequencies simultaneousl y. Several experiments were conducted in this study to lest the perfor mance of the advanced multi-point LDV. We confirmed that the advanced multi-point LDV could be a useful, compact and inexpensive optical mea suring instrument for obtaining the information of a velocity field as a function of time and position.