10 likes | 155 Views
STUT. Development of a Dual-Wavelength Optical Phase Measurement instrument. Ruey-Ching Twu* , Hong-Yao Hou, and Yi-Huan Lee Department of Electro-Optical Engineering, Southern Taiwan University, Tainan 710, Taiwan E-mail : rctwu@mail.stut.edu.tw. Introduction.
E N D
STUT Development of a Dual-Wavelength Optical Phase Measurement instrument Ruey-Ching Twu*, Hong-Yao Hou, and Yi-Huan Lee Department of Electro-Optical Engineering, Southern Taiwan University, Tainan 710, Taiwan E-mail : rctwu@mail.stut.edu.tw Introduction In this study, a common-path optical homodyne polarization interferometer is proposed to demonstrate the dual-wavelength phase measurements performed in a LabVIEW-based instrument. A Zn-indiffused phase modulator (ZIPM) fabricated in an x-cut/z-propagation lithium niobate (LN) substrate that is used for phase modulations of both wavelengths. The simultaneous phase measurements can be achieved by utilizing the parallel processing and multiplexed capability in the LabVIEW platform. The experimental results show that the simulated phases from the ZIPM can be extracted and real-time display shown on the designed LabVIEW front panel. Measurment Setup Experimental Results Fig. 1. The measurement setup. Fig. 3. Phase variations as a function of time under the simulated applied voltages: (a) Vdc=2V and (b) Vdc=4V. The phase curves are repeatable and the biases are stable for the 632.8nm (1) wavelength. However, the repeatable phase curves with gradually shifting biases are observed for the 532nm (2) wavelength due to more sensitivity photorefractive effect in the LN crystals. Fig. 2. The designed LabVIEW front panel with a real-time display on the measured data.All the analyzed signals and calculated results including interferometric intensities (P), FFT spectrum, harmonic intensities (I), ratio of different harmonic intensities, and phase variations ( ) can be monitored with the flexible design of LabVIEW front panel. Conclusions We proposed and demonstrated a novel dual-wavelength phase measurement instrument by employing an optical homodyne technique. The received signal and data process is performed in the LabVIEW platform. Future work will demonstrate this instrument for a variety of industrial and scientific applications. References 1) F. Bien, M. Camac, H. J. Caulfield, and S. Ezekiel: Appl. Opt. 20 (1981) 400 2) B. Chen, X. Cheng, and D. Li: Appl. Opt. 41 (2002) 5933 3) C. E. Towers, D. P. Towers, D. T. Reid, W. N. MacPherson, R. R. J. Maier, and J. D. C. Jones: Optics Lett. 29 (2004) 2722 4) R. C. Twu, H. Y. Hong, and H. H. Lee: Opt. Express 16 (2008) 4366