Fabry-Perot Interf erometer의 제작 및 응용에 관한 연구

Abstract

평면특수 유리에 Aluminum Coating을 한 후 그 위에 Silica를 입혀 만든 etalon판을 지지대에 고정시킨 Fabry-Perot etalon 부분과 부수기구로써 압력변화용 진공장치 및 D. C. Amplifer를 제작하고 이 장치를 이용해서 공기의 굴절율을 측정하여 제작된 F-P interferometer의 정밀도를 알아보았다. F-P interferometer 제작에서 etalon판은 지름 26.4mm, 두께 6.5mm인 Synthetic silica 재료에 aluminum coating하였고 etalon판 지지대는 etalon판을 전·후로 조정하고 그것을 다시 미세조정 할 수 있도록 만들었으며, 압력변화때 etalon지지대가 움직여 장 치의 center에 변화가 없도록 etalon지지대의 자기화에 의해 지지대와 밀착 고정되도록 평면 철판을 깔았다. 제작된 F-P interferometer로 공기의 굴절율을 측정할때 사용한 light Source와 파장은 Hg-Lamp의 λ_(Hg)=5461Å과 He-Ne Laser의 λ=6328Å로써 각 단색광을 F-P interferometer에 투과시켜 공기의 압력변화에 따른 간섭무늬의 이동수와 diameter를 육안과 traveling microscope로 측정하였다. 측정한 결과 λ_(Hg)=5461Å을 사용했을때 공기의 굴절율은 n_(i)=1.000255로, λ_(He-1)=6328Å을 사용했을 때 n_(i)=1.0002291이었고, 이 값을 국제분광학 의회에서 채택한 이론식을 써서 계산한 것인 λ=5461Å일 때 n_(i)=1.0002780, λ=6328Å일때의 n_(i)=1.0002766와 비교해 보면 약 2/1000%의 오차로 나타나 정확함을 알 수 있었으며, 따라서 제작한 F-P interferometer의 실용도는 상당한 수준의 것으로 볼 수 있다.;This study was conducted to manufacture F-P interferometer and to examine the accuracy of this apparatus. F-P interferometer was assembled with a etalon plate and its supporting stand. Etalon plate was prepared by coating a flat special glass first with aluminum and then with silica. Vacuum chamber and D.C.Amplifier were also manufactured to accompany with F-P int. In order to examine the accuracy of this manufactured F-P interferometer, the reflective index of air was determined employing this apparatus. Etalon plate was made of synthetic silica(26.4mm diameter, 6.5mm thickness) plate coated with aluminum. Supporting stand was manufactured to be able to not only shift etalon plate back and forth but also make fine adjustments. The flat iron plate was laid on the botton of the vacuum chamber so as to attach supporting stand firmly to the iron plate by the magnetic induction. Thus, supporting stand was protected from shifting according to the pressure change occuring, thereby having the center of the apparatus remained stationary. Light sources and waves used in determining the reflection index of air by F-P int. were Hg-Lamp with λ_(Hg)=5461 Å and He-Ne Laser with λ=6328 Å. When each monochromatic light was projected into F-P int., the number of the shifted interfered fringes and their diameter occurring due to the changes in air pressure were determined both by naked eyes and traveling microscope. The reflective index of air were n₁=1.000255 and n₁=1.0002291 employing λ_(Hg)=5461 Å and λ_(He-Ne= 6328 Å, respectively. Employing theoretical formula adopted by International Spectroscopy Council n₁=1.0002780 and n₁=1.0002766 were obtained, when λ_(Hg)5461 Å and λ_(He·Ne)= 6328 Å were used as light sources and wave length, respectively these figures were equal to the data abtained in this study employing F-P int. Within a 2/1000% of error. Therefore the utility of the F-P int. manfufactured in this study was proved to be high.