Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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Optical Microphone Based on a Reflective Micromirror Diaphragm

반사형 마이크로 미러를 이용한 광마이크로폰

  • Song, Ju-Han (Department of Electronic Engineering, Kwangwoon University) ;
  • Lee, Sang-Shin (Department of Electronic Engineering, Kwangwoon University)
  • Published : 2006.04.01
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Abstract

An optical microphone incorporating a reflective diaphragm and a fiber-optic head was demonstrated. The diaphragm was made of a micromirror membrane which is suspended by a silicon bar connected to a frame, allowing fer a displacement induced by acoustic waves. A compact, simple optical head was implemented by exploiting a single multimode fiber. For the assembled microphone, the static characteristics were investigated to find the operation point defined as the optimum distance between the head and the diaphragm, and a flat frequency response with a variation of $\sim$2dB for the range of up to 2 kHz was accomplished.

본 논문에서는 마이크로 미러 진동판을 이용한 광마이크로폰을 제안하고 구현하였다. 이 미러 진동판은 실리콘 바(bar)에 의해 프레임에 연결되어 있어서 인가된 음압에 따라 전후로 움직이게 되어 있으며, 작고 간단한 구조의 광 헤드는 한 개의 다중모드 광섬유로 되어 있다. 본 논문에서는 광헤드와 진동판 사이의 거리를 변화시켜 가면서 응답특성을 측정하여 선형성과 민감도가 최대인 지점을 동작점으로 결정하였다. 그리고 음성신호의 주파수를 변화시켜 가면서 구현된 소자의 출력을 측정하였다. 측정된 광마이크로폰의 주파수 대역폭은 약 $\sim$2dB 출력 변화 이내에서 약 2 kHz였다.

Keywords

References

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Cited by

  1. Analysis of Frequency Response Characteristics in Optical Microphone vol.8, pp.6, 2008, https://doi.org/10.5392/JKCA.2008.8.6.008