TY - GEN
T1 - Development of a new optical heterodyne microscopes for fluid velocity measurements in a micro-channel
AU - Lo, Yu Lung
AU - Chuang, Gi Shing
AU - Chuang, Han Sheng
PY - 2002/12/1
Y1 - 2002/12/1
N2 - An experiment based on a new optical heterodyne interferometer with microscopic probe has been developed in order to measure the fluid velocity in a micro-channel. By implementing laser Doppler anemometry (LDA) into a microscope, the laser beams are transmitted and then focused on the spot with an extremely highly spatial resolution over an area in 10 μ m diameter. The laser beams are modulated by a diffractive grating in sinusoidal backward and forward movement using a PZT stack, and the standard heterodyne signal, therefore, is recovered by a new demodulation system. In this study, nano-size of particles in 75 μm inner diameter of a micro-channel is driven by a LC pumping. As a result, the trace of velocity of particles can be recorded by a new optical heterodyne microscope. As compared to the other existing heterodyne techniques applied in the fluid velocity measurements, this new technique shows a better frequency response, a wider modulation frequency and an easier and cheaper setup. This setup, however, is limited by the performance of a PZT stack that is used to modulate a diffractive grating. In conclusion, a laser Doppler microscope implemented by a new heterodyne technique is a practical instrument for the micro fluid investigations, especially in MEMS and biological researches.
AB - An experiment based on a new optical heterodyne interferometer with microscopic probe has been developed in order to measure the fluid velocity in a micro-channel. By implementing laser Doppler anemometry (LDA) into a microscope, the laser beams are transmitted and then focused on the spot with an extremely highly spatial resolution over an area in 10 μ m diameter. The laser beams are modulated by a diffractive grating in sinusoidal backward and forward movement using a PZT stack, and the standard heterodyne signal, therefore, is recovered by a new demodulation system. In this study, nano-size of particles in 75 μm inner diameter of a micro-channel is driven by a LC pumping. As a result, the trace of velocity of particles can be recorded by a new optical heterodyne microscope. As compared to the other existing heterodyne techniques applied in the fluid velocity measurements, this new technique shows a better frequency response, a wider modulation frequency and an easier and cheaper setup. This setup, however, is limited by the performance of a PZT stack that is used to modulate a diffractive grating. In conclusion, a laser Doppler microscope implemented by a new heterodyne technique is a practical instrument for the micro fluid investigations, especially in MEMS and biological researches.
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M3 - Conference contribution
AN - SCOPUS:0141649529
SN - 7560317685
T3 - Proceedings of the Second International Symposium on Instrumentation Science and Technology
SP - 4/649-4/653
BT - Proceedings of the Second International Symposium on Instrumentation Science and Technology
A2 - Fan, K.-C.
A2 - Yetai, F.
A2 - Fan, K-.C.
A2 - Yetai, F.
T2 - Proceedings of the International Symposium on Precision Mechanical Measurement
Y2 - 11 August 2002 through 16 August 2002
ER -