A STUDY ON THE SPATIAL LIGHT MODULATOR WITH PISTON PLUS TILT MODE OPERATION USING SURFACE MICROMACHINING TECHNOLOGY

표면 미세 가공 기술을 이용한 상하운동 및 회전운동을 하는 광 변조기에 관한 연구

  • Published : 2000.02.01

Abstract

In this paper, using surface micromachining technology with thick photoresist and aluminum, an SLM(Spatial Light Modulator), which is applied to the fields of adaptive optics and pattern recognition system, was fabricated and the electromechanical properties of the fabricated micro SLM are measured. In order to maximize fill-factor and remove mechanical coupling between micro SLM actuators, the micro SLM is composed of three aluminum layers so that spring structure and upper electrode are placed beneath the mirror plate, and $10\times10$ each mirror plate is individually actuated. Also, the micro SLM was designed to be able to modulate phase and amplitude of incoming light in order to have a continuity of phase modulation of incoming light. In the case of amplitude and phase modulation, maximum vertical displacement is 4$\mum$, and maximum angular displacement is $\pm4.6^{\corc}$ respectively. The height difference of the fabricated mirror plate was able to be reduced to 1100A with mirror plate planarization method using negative photoresist(AZ5214). The electromechanical properties of the fabricated micro SLM were measured with the optical measurement system using He-Ne laser and PSD(position sensitive device).

Keywords

References

  1. Robert K. Tyson, Principles of Adaptive Optics, Academic Press, San Diego, CA, 1990
  2. Martin Yellin,'USING MEMBRANE MIRRORS IN ADAPTIVE OPTICS,' Proc. SPIE, vol. 75, pp. 97-102, 1976
  3. Mark A. Ealey and John F. Washeba, 'Continuous facesheet low voltage deformable mirrors,' Opt. Eng. vol. 29, no. 10, pp. 1191-1198, Oct. 1990 https://doi.org/10.1117/12.55715
  4. G. Vdovin, P. M. Sarro, and S. Middelhoek, 'Technology and application of micromachined adaptive optics,' Journal of Micromechanics and Microengineering, vol. 9, no. 2, R8-R20, June, 1999 https://doi.org/10.1088/0960-1317/9/2/202
  5. Thomas. G. Bifano, Julie Perreault, Raji Krishnamoorthy Mali, and Mark N. Horenstein, 'Microelectromechanical Deformable Mirrors,' IEEE Journal of selected topics in quantum electronics, vol. 5, no. 1, pp. 83-89, Jan./Feb. 1999 https://doi.org/10.1109/2944.748109
  6. Guo-Dung J. SU, Li FAN, and Ming C. Wu, 'SURFACE-MICROMACHINED ADAPTIVE MICROMIRROR ARRAYS WITH LARGE STROKES,' Transducers'99, pp. 578-581, June 7-10, Sendai, Japan, 1999
  7. J.E. Pearsov and S. Hansen, 'Experiment studies of a deformable-mirror adaptive optical system,' Journal of the Optical Society of America, vol. 67, no. 3, pp. 325-333, March, 1977
  8. Seok-Whan Chung and Yong-Kweon Kim, 'Fabrication and Measurement of 10x10 micro SLM array for phase and amplitude modulation,' MOEMS'99, Mainz, Germany, pp. 49-53, 1999
  9. S. W. Chung, and Y. K. Kim, 'Measurements of a Fabricated Micro Mirror Using a Lateral-Effect Position-Sensitive Photodiode,' Transactions on Industrial Electronics, vol. 45, no.6, pp. 861-865, Dec., 1998 https://doi.org/10.1109/41.735329