Laser Doppler Vibrometry System using the Synthetic-Heterodyne ...

CSNDSP08 - 136 - ProceedingsV. CONCLUSIONSA simple out-of-plane multipoint LDV systemincorporating HOEs and a CMOS DSP camera was shownto be able to detect vibration signals at frequencies up to100 Hz from a vibrating surface. The CMOS DSP cameraallows for random pixel access thereby enabling the userto examine particular regions of interest on the vibratingsurface. Improvements in the stability of the processedsignal can be expected by using a more stable laser.REFERENCES[1] D.A. Jackson, A.D Kersey, M. Corke M and J.D. Jones, “Pseudoheterodynedetection scheme for optical interferometers,”Electron. Lett., vol. 18, pp. 1081–3, 1982.[2] A. Dandridge, A.B. Tveten and T. Giallorenzi, “Homodynedemodulation scheme for fiber optic sensors using phasegenerated carrier,” IEEE J. Quantum Electron., vol. 18 pp. 1647–62, 1982.[3] J.H. Cole, B.A. Danver and J.A. Bucaro, “Synthetic-heterodyneinterferometric demodulation,” IEEE J. Quantum Electron., vol 18pp. 694–7, 1982.[4] B. Griffin and M.J. Connelly, “Interferometric fiber optic sensorinterrogation system using digital signal processing and syntheticheterodynedetection,” 17th International Conference on OpticalFibre Sensors, Proceedings of SPIE., vol. 5885, pp. 619-622,2005.[5] M. Holzer and F. Mohr, “Aspects of signal processing in laservibrometry and their embedded-realisation on FPGA with NI-LabVIEW,“ 17th International Conference Radioelektronika,2007.[6] P. Castellini, G.M. Revel and E.P. Tomasini, “Laser Dopplervibrometry: a review of advances and applications,” The ShockVibr. Dig., vol. 30, pp. 443-456, 1998.[7] P. Egan, M.J. Connelly, F. Lakestani and M.P. Whelan, “Randomdepth access full-field heterodyne low coherence interferometryutilizing acousto-optic modulation and a complementary metaloxidesemiconductor camera,” Optic Lett. vol. 31, pp. 912-914,2006.[8] P. Egan, F. Lakestani, M. P. Whelan and M.J. Connelly, “Fullfieldoptical coherence tomography with a CMOS-DSP camera,”Opt. Eng., vol. 45, pp. 015601-6, 2006.[9] M.J. Connelly, P. Szecowka, R. Jallapuram, S. Martin, V. Toaland M.P. Whelan, “Multipoint laser Doppler vibrometry usingholographic optical elements and a CMOS digital camera,” Opt.Lett., vol. 33, pp, 330-332, 2008.[10] M.J. Connelly, “Digital synthetic-heterodyne interferometricdemodulation,” J. Opt. A: Pure and Applied Optics, vol. 4, pp.400-405, 2002.[11] Characterisation data on Hitachi Fabry-Perot laser diodeswww.photonic-products.com/techinfo/hitachi_tech/opd_databook_mar031.pdf