Formation of high quality interference fringes from both sides of a suitably designed hololens in the laser Doppler anemometer measurement volume

We report, for the first time to the best of our knowledge, the formation of high quality, evenly spaced, undistorted fringes in the measurement volume of a laser Doppler anemometer from both sides of a suitably designed hololens. Experiments are performed for the analysis of fringes formed at the measurement volume by real time monitoring and actual fringe field analysis techniques. The results indicate the qualitative as well as quantitative improvement of 66.58% in overall average normalised standard deviations of the width of the fringes formed by the proposed imaging configuration than that of the conventional imaging configuration.