Patel, Rikesh and Achamfuo-Yeboah, Samuel and Light, Roger and Clark, Matt (2011) Widefield heterodyne interferometry using a custom CMOS modulated light

In this paper a method of taking widefield heterodyne interferograms using a prototype modulated light camera is described. This custom CMOS modulated light camera (MLC) uses analogue quadrature demodulation at each pixel to output the phase and amplitude of the modulated light as DC voltages. The heterodyne interference fringe patterns are generated using an acousto-optical frequency shifter (AOFS) in an arm of a Mach-Zehnder interferometer. Widefield images of fringe patterns acquired using the prototype MLC are presented. The phase can be measured to an accuracy of ±6.6◦. The added value of this method to acquire widefield images are discussed along with the advantages. © 2011 Optical Society of America OCIS codes: (100.3175) Interferometric imaging; (110.3175) Interferometric imaging. References and links 1. N. A. Riza and M. A. Arain, “Angstrom-range optical path-length measurement with a high-speed scanning heterodyne optical interferometer,” Appl. Opt. 42, 2341–2345 (2003). 2. V. Ganapathi, C. Plagemann, D. Koller and S. Thrun, “Real time motion capture using a single time-of-flight camera,” Proc. IEEE Comput. Sci. Conf. on Comput. Vision Pattern Recognit., 755–762 (2010). 3. D. Droeschel, D. Holzand, S. Behnke, “Multi-frequency phase unwrapping for time-of-flight cameras,” IEEE/RSJ 2010 Int. Conf. Intell. Rob. Syst. 66, 1463–1469 (2010). 4. X. Luan, R. Schwarte, Z. Zhang, Z. Xu, H.G. Heinol, B. Buxbaum, T. Ringbeck, and H. He, “3D intelligent sensing based on the PMD technology,” Proc. SPIE 4540, 482–487 (2001). 5. R. Onodera and Y. Ishii, “Two-wavelength laser-diode heterodyne interferometry with one phasemeter,” Opt. Lett. 20, 2502–2502 (1995). 6. S. Yokoyama, J. Ohnishi, S. Iwasaki, K. Seta, H. Matsumoto, and N. Suzuki, “Real-time and high-resolution absolute-distance measurement using a two-wavelength superheterodyne interferometer,” Meas. Sci. Technol. 10, 1233 (1999). 7. S. Vergamota, L. Cupido, M. Manso, F. Eusebio, A. Silva, P. Varela, J. Cabral, F. Serra, and C. Varandas, “Microwave interferometer with a differential quadrature phase detection,” Rev. Sci. Instrum. 66, 2547–2547 (1995). 8. H.-K. Teng and K.-C. Lang, “Heterodyne interferometer for displacement measurement with amplitude quadrature and noise suppression,” Opt. Commun. 280, 16–22 (2007). 9. S. Chamberlain and J. Lee, “Novel wide dynamic range silicon photodetector and linear imaging array,” IEEE J. Solid State Circuits 20, 41–48 (1984). 10. F. G. Cervantes, G. Heinzel, A. F. G. Marin, V. Wand, F. Steier, O. Jennrich, and K. Danzmann, “Real-time phase-front detector for heterodyne interferometers,” Appl. Opt. 46, 4541–4548 (2007). 11. A. Kimachi, “Real-time heterodyne imaging interferometry: Focal-plane amplitude and phase demodulation using a three-phase correlation image sensor,” Appl. Opt. 46, 87–94 (2007). 12. A. Kimachi, “Real-time heterodyne speckle pattern interferometry using the correlation image sensor,” Appl. Opt. 49, 6808–6815 (2010). #156044 $15.00 USD Received 4 Oct 2011; revised 3 Nov 2011; accepted 4 Nov 2011; published 15 Nov 2011 (C) 2011 OSA 21 November 2011 / Vol. 19, No. 24 / OPTICS EXPRESS 24546 13. P. Dmochowski, B. Hayes-Gill, M. Clark, J. Crowe, M. Somekh, and S. Morgan, “Camera pixel for coherent detection of modulated light,” Electron. Lett. 40, 1403–1404 (2004). 14. D. Summers, M. Clark, I. Stockford, S. Achamfuo-Yeboah, and J. Pereira Do Carmo, “Modulated light camera for space applications and assessment via a test bench system,” Acta Astronaut. 66, 1399–1403 (2010). 15. M. Pitter, R. Light, M. Somekh, M. Clark, and B. Hayes-Gill, “Dual-phase synchronous light detection with 64 x 64 CMOS modulated light camera,” Electron. Lett. 40, 1404–1406 (2004). 16. N. Johnston, C. Stewart, R. Light, B. Hayes-Gill, M. Somekh, S. Morgan, J. Sambles, and M. Pitter, “Quad-phase synchronous light detection with 64 x 64 CMOS modulated light camera,” Electron. Lett. 45, 1090–1092 (2009).