The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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Design of a Wide-band Acousto-Optical Spectrometer for Radio Astronomical Observations

우주전파 관측을 위한 광대역 음향광학 전파분광기 설계

  • Published : 2001.10.01
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Abstract

The acousto-optical spectrometer is designed by using 1 GHz bandwidth acousto-optic deflector for radio signal analysis. This system is a high resolution wide band spectrometer which uses I GHz bandwidth and a total of 2,048 channel charge coupled device. When we measured the spectrums of signals deflected by acousto-optical spectrometer, we confirmed the stability of the total system by repetitive observations of the same frequency, and each part of the system worked well. We installed this system onto 60 cm radio telescope, and observed 12CO(J= 1 ∼0) emission lines around CRL 2688, IRC 10216 and NGC 5005 Galaxy center. We could observe effectively very narrow band width radio spectrum as well as wide band radio spectrum. We also confirmed high sensitivity and resolution in observation of 12CO(J-10) omission line of NGC 5005 Galaxy center which is a weak signal.

우주전파의 신호를 관측하기 위한 1 GHz대역의 음향광학 전파분광기를 설계.제작하였다. 이 전파분광기는 다중채널 방식의 신호의 세기가 미약한 우주 전파신호를 분석하기 위한 초고감도의 전파 분광기로, 관측되는 스펙트럼의 모양을 상세히 측정할 수 있는 전파분광기이다. 주파수 분해능과 광대역 주파수 성분을 포함하는 이 음향광학 전파분광기의 광원(optical source)으로는 He-Ne 레이저를 사용하였고, 1 GHz에서 2 GHz까지의 대역폭을 갖는 광대역 GaP 광펼향 소자를 사용하였으며, 광신호 검출을 위해 2,048 채널의 CCD를 사용하였다. 전파망원경을 통해 우주전파신호인 CRL 2688, IRC 10216 그리고 NGC 5005 은하 중심의 12CO(J= 1 ~0) 분자선(molecular line)을 관측한 결과, 광대역의 특성을 가지며 주파수 분해능이 양호함을 확인하였다.

Keywords

References

  1. Ann. Physics, 9th Series v.17 Diffusion of light and X Rays by a homogeneous Transparent Body I. Brillouin
  2. Fundamentals of Photonics B. A Saleh;M. C. Teich
  3. IEEE Spectrum Interaction between Light and Sound R. Adler
  4. Acousto-Optics J. Spriel
  5. IRE Int. Conv. v.Re 6 no.69 Wide band instantaneous spectrum analyzers employing delay line light Modulators L. B. Lambert
  6. Proceedings of the IREE Australia A Broad-band Radio Astonomy Spectrometer D. K. Milne;T. W Cole
  7. Publ.;Astronomy Society of Japan v.29 A High resolution acousto-optical radio spectrometer for millimeter-wave astronomy N. Kaifu;N. Ukita;Y. Chikada;T. Miyashi
  8. NRAO internal report no.293 Hybrid spetrometer user manul A. Dowd
  9. IEEE Trans . on Instrum. Meas v.IM-34 no.4 Analog-Filter Digital-Correlator Hybrid Spectrometer S. Weinreb
  10. Publ. Astron. Soc. A 1.5-m Millimeter-Wave Telescope with Acousto-Optical Spectrometers at Nagoya University T. Takano(et.al)
  11. Chinese Journal of Acoustics v.10 no.1 The Frequency Resolution of Acousto-Optical Spectrometer J. Wang;J. Shen
  12. Astronomy and AStrophysics v.114 A Stable Acousto-Optical Spectrometer for Millimeter Radio Astronomy C. R. Masson
  13. Proceedings of SPIE v.231 The design of stable Acousto-Optical Spectrometers for Radio Astronomy C. R. Masson
  14. Proceedings of the IEEE v.69 no.1 Acousto-Optics-A Review of Fundamentals A. Korpel
  15. The Cologne Acousto-Optical Spectrometers, Experimental Astronomy, Kluwer Academic Publ. R. Schieder;V. Toll;G. Winnewisser
  16. Proceeding of the IEEE v.61 no.8 Acoustoopic Deflection Materials and Techinques N. Uchida;M. Niizeki
  17. Proceeding of the IEEE v.54 no.10 A Review of Acoustooptical Deflection and Modulation Device E. I. Gordon