Abstract: The present disclosure relates to a velocity interferometer. The interferometer described herein, comprises of two optical cells, one partially containing a liquid. The light entering the interferometer is amplitude split and made to propagate through the two cells in such a way that the apparent path lengths of the beams are equal, thereby fulfilling the condition necessary for obtaining single wide fringe in the interference pattern of the two beams. However, due to difference in the physical path traversed by the two beams, a finite delay time exists between them. The two beams, after reflection from end-mirrors or cube corner prisms in the two cells are recombined to form interference fringe patterns on active areas of multiple detectors. Doppler shifted light resulting from reflection of light from a moving projectile generate fringe shifts on the detector planes thereby producing voltage signals proportional to instantaneous velocity of fast moving projectile.

Abstract: The present disclosure relates to a velocity interferometer. The interferometer described herein, comprises of two optical cells, one partially containing a liquid. The light entering the interferometer is amplitude split and made to propagate through the two cells in such a way that the apparent path lengths of the beams are equal, thereby fulfilling the condition necessary for obtaining single wide fringe in the interference pattern of the two beams. However, due to difference in the physical path traversed by the two beams, a finite delay time exists between them. The two beams, after reflection from end-mirrors or cube corner prisms in the two cells are recombined to form interference fringe patterns on active areas of multiple detectors. Doppler shifted light resulting from reflection of light from a moving projectile generate fringe shifts on the detector planes thereby producing voltage signals proportional to instantaneous velocity of fast moving projectile.

Abstract: A device for generating optical vortex of desired topological charge is disclosed. The device comprises a circular mirror having hole at its centre and a radial slit. The mirror comprises a piezoelectric actuator. The actuator comprises a hollow tube having inner diameter equal to the diameter of the hole of the mirror, a through cut extending along the length of the tube from an inner till an outer diameter, and an inner and outer electrode being formed on inner and outer wall of the tube respectively, wherein the length of the electrode increases continuously in the azimuth direction across said outer wall. The Actuator is coaxially joined to the mirror such that the slit formed between the inner and outer diameter of the tube overlaps with the radial slit. Shape of the mirror undergoes azimuthal expansion upon applying excitation voltage across electrodes forming single turn helix to generate optical vortex.

Abstract: A device for generating optical vortex of desired topological charge is disclosed. The device comprises a circular mirror having hole at its centre and a radial slit. The mirror comprises a piezoelectric actuator. The actuator comprises a hollow tube having inner diameter equal to the diameter of the hole of the mirror, a through cut extending along the length of the tube from an inner till an outer diameter, and an inner and outer electrode being formed on inner and outer wall of the tube respectively, wherein the length of the electrode increases continuously in the azimuth direction across said outer wall. The Actuator is coaxially joined to the mirror such that the slit formed between the inner and outer diameter of the tube overlaps with the radial slit. Shape of the mirror undergoes azimuthal expansion upon applying excitation voltage across electrodes forming single turn helix to generate optical vortex.