Four-bucket 알고리즘을 이용한 레이저 간섭계 = Multiphase homodyne laser interferometer with four bucket

다국어 초록 (Multilingual Abstract)

By tilting the reference mirror of Twynman-Green interferometer having a reference mirror and a moving mirror, fringe pattern composed of bright and dark parallel lines can be obtained and the fringe pattern is shifted according to the displacement of the moving mirror. Several studies are executed for displacement measurement by detecting the intensity of the fringe with photo-diodes having small detecting area. In this study, to improve the sensitivity and robustness, the intensity of fringe is detected by using a large-area quadratic photo-diode masked with a grating panel having four kinds of binary grating having phase-difference of 0, π/4, π/2, 3π/4. The phase of the fringe is calculated with a simple 4-buckets algorithm. A experimental result shows that standard deviation of 5.653 nm is obtained comparing with a capacitive type gap sensor having nearly 1 nm accuracy.

목차 (Table of Contents)

• 1. 서론
• 2. 간섭무늬 형성과 해석
• 3. 실험
• 3.1 실험 장치의 구성
• 3.2 실험 결과 및 고찰
• 4. 결론
• 후기
• 참고문헌