Integrated laser Doppler velocimeter for fluid velocity and wall friction measurements

A fully integrated laser Doppler velocimeter sensor is presented in this paper. The size of the sensor head is 4 mm width by 2 cm long. The fabrication of the whole system is described and optical characterizations are thoroughly discussed Wall friction measurements are compared, with a good agreement to other measurement techniques. Finally, the possibility of measuring velocity from the light diffused by submicrometer particles is discussed.