Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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Simultaneous Measurement of Thickness and Refractive Index of Transparent Material Using a Collimated Beam Having a Finite Radius

유한 반경의 시준 광속을 이용한 투명 매질의 두께와 굴절률의 동시 측정

  • Park, Dae-Seo (School of Information and Communication Engineering, Inha University) ;
  • O, Beom-Hoan (School of Information and Communication Engineering, Inha University) ;
  • Park, Se-Geun (School of Information and Communication Engineering, Inha University) ;
  • Lee, El-Hang (School of Information and Communication Engineering, Inha University) ;
  • Lee, Seung-Gol (School of Information and Communication Engineering, Inha University)
  • 박대서 (인하대학교 정보통신공학부) ;
  • 오범환 (인하대학교 정보통신공학부) ;
  • 박세근 (인하대학교 정보통신공학부) ;
  • 이일항 (인하대학교 정보통신공학부) ;
  • 이승걸 (인하대학교 정보통신공학부)
  • Published : 2009.02.25
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Abstract

We propose a new measuring technique based on optical low-coherence reflectometry that enables us to determine the refractive index and the geometrical thickness of a transparent sample by one-time scanning only. By passing a collimated beam having a finite size through the edge of the sample, the refractive index and the geometrical thickness can be determined simultaneously from the comparison of interferograms generated by two kinds of reflected beams. In this study, a refractive index could be determined with the accuracy of $10^{-3}$, and its accuracy would be enhanced by using a more precise translator and a thicker sample.

본 연구에서는 저간섭성 반사계(Optical low-coherence reflectometry)를 이용하여 한 번의 측정으로 투명 시료의 두께와 굴절률을 동시에 측정하는 기술을 제안하였다. 제안된 방법은 유한 반경을 가진 시준된 광속을 시료의 경계 영역으로 입사시키는 것으로써, 시료가 있는 부분과 없는 부분으로부터 반사된 광속에 의한 간섭 무늬들을 한 번에 획득할 수 있다. 한번의 측정을 통해 얻어진 두 종류 간섭 무늬들의 상대적인 위치 차이를 이용하여 시료의 두께와 굴절률을 동시에 결정할 수 있었다. 굴절률의 정밀도는 이송장치의 위치 정밀도가 향상되고, 시료의 두께가 두꺼워 질수록 개선될 수 있으며, 본 실험에서는 약 $10^{-3}$의 정밀도로 굴절률을 결정할 수 있었다.

Keywords

References

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