Study on Full-field Dynamic Photo-elastic modulated Phase-shifting Interferometry

• Main Authors: PENG, ZENG-YI, 彭增億
• Other Authors: HAN, CHIEN-YUAN
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/91058270924086852371

碩士 === 國立聯合大學 === 光電工程學系碩士班 === 104 === This study was proposed based on Photoelastic Modulator (PEM) and phase-shift technique the purpose uses phase delay of the regulatory mechanism to achieve the effect of phase shifting interferometry and obtain a sample to be measured interference fringes quickly . Although the liquid crystal tunable phase delay and the light elastic modulator is also part of phase modulation technique. However, in the liquid crystal phase adjustable delay and relative to wavelength dependent and operate wavelength range is narrow the response is slow、susceptible to temperature change produces a phase wavefront . Therefore photoelastic modulator having characteristics such as: large aperture、large viewing angle (about ±40º)、high modulation frequency (20 ~ 100KHz) and stable. It can be accurately control the phase delay replace the liquid crystal error on system. Utilizing photoelastic modulator and assort the Stroboscopic Illumination and photoelastic modulation cycle four specific phases of the irradiation time. So that the introduction of the phase difference between the reference end and the sample end. The experiment measured amount of mirrors and lenses as standard samples analyzed interference image and using the onion epidermal to plant cells osmosis. Using brine was dropped in onion epidermal cells reach the characteristic patterns of atrophy structural changes. Finally, using four-step phase shift method and Phase Unwrapping a phase distribution to that of the analyte.