푸리에 변환 분광기 (Fourier Transform Spectrometer)

1 1. FTS .. (Fourier Transform Spectrometer) : ( , ) (1) ; (2) ; (3) (Fourier Transform Spectrometer; FTS) (Fabry Perot Interferometer; FPI) . FTS (double beam interference) FPI (multi beam interference).

2 , . FTS FPI 2 . (R > 10,000) .. FTS FPS (Connes 1970; Ridgway & Brault 1984). FTS FTS (Michelson interferometer) . 2 (beamsplitter) . (optical path difference; Number [um-1]IntensityInput SpectrumOutput Spectrum 3.)

3 FTS . (apodization) .OPD) , . (interferogram) . Number [um-1] Path Difference [um]Measured Intens 2. ( ) FTS ( ). :[] +=maxmin)2cos(1)(21)( dpIpF. p , (wave number, ) .. 2 (monochromatic line) , (sinusoidal function) . (inverse Fourier Transform ) , =maxmin)2cos()()(ppFTSdpppFI ,FTS ( 3 ).

4 Pmax pmin FTS FTS . FTS FWHM (Full Width at Half Maximum) .FWHMFWHMpp = , , Np Nyquist .SPNp =)2(maxmax 2 Nyquist , S (over sampling factor) . 3 FTS (apodization) . (Window Function or Apodization Function) . Hamming Gauss.

5 FTS FTS - Multiple Number [um-1]IntensityInput SpectrumOutput Spectrum FTS Interferogram - Multiple Lines-10-5051002040608010012014016018020 0 Optical Path Difference [um]Measured Intensity 4. ( ) ( ).FPI , FTS . 4 4 FTS - Multiple Number [um-1]IntensityInput SpectrumOutput Spectrum 5. 4 .. 6. AKARI FIS (Far Infrared Surveyor) FTS (Kawada et al.)

6 2004, Takahashi et al. 2002). , FTS . 5 .FPI . FTS .. , . FTS FPI . , , FTS (pmax pmin) .. FTS ..FTS 50%.

7 (photon noise) ..FTS , CCD (infrared array) . , . , FTS .FTS FTS , .. AKARI FIS (Far Infrared Surveyor; Kawada et al. 2004, Takahashi et al. 2003) FTS ( 6, 2007 ), Herschel SPIRE FTS (Swinyard et al. 2003). FTS.

8 1970 FTS . , . FTS .FTS , . , , .. Connes, P. 1970, Ann. Rev. Astron. Astrophys., 8, 209 Kawada, M., Shibai, H., Kaneda, H., & Nakagawa, T. 2004, Proceedings of the SPIE, 5487, 359 Ridgway, S. T., & Brault, J. W. 1984, Ann. Rev. Astron. Astrophys., 22, 291 Swinyard, B. M., et al. 2003, Proceedings of the SPIE, 4850, 698 Takahashi, H.

9 , Kawada, M., Murakami, N., Ozawa, K., Shibai, H., & Nakagawa, T. 2003, Proceedings of the SPIE, 4850, 191