One-dimensional interferometric Rayleigh scattering velocimetry using a virtually imaged phased array

One-dimensional interferometric Rayleigh scattering velocimetry is demonstrated using a virtually imaged phased array (VIPA). A continuous-wave laser emitting at 532 nm is used as the source, and a low-noise CCD camera is used as the detector. The VIPA has a free spectral range of 15 GHz and is coated for the wavelength range 500-600 nm. Velocity measurements at different flow rates show an accuracy of 10 m/s. Demonstration of high-speed flow velocity measurement is conducted in a jet of air through a contoured converging nozzle. Factors considered for the optimization of the system are discussed along with possibilities of extending the strategy to other measurement techniques.