• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.50-51
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• 2000

최근에 결상광학계는 광학유리를 사용한 전통적인 단순 구면형에서 플라스틱, 금속 등의 소재와 비구면 혹은 홀로그래피 광학소자를 이용한 복합적 기능형으로 발전하고 있다. 또한 엑스선에서 적외선까지 매우 넓은 분광영역에서 현미경으로 관찰할 수 있는 미소광학소자부터 구경 10 m 정도의 대구경 망원경까지 다양한 크기의 초정밀 결상광학계가 계속 개발되고 있다. 즉 구경 100 mm 정도의 구면 광학계에서 광대역 분광영역의 대구경 비구면 광학계로 발전하고 있다.$^{(1)}$ (표 1 참조) (중략)

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.4
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• pp.950-967
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• 1995

Acoustic holography makes it possible to reconstruct the acoustic field based on the measurement of the pressure distribution on the hologram surface. Because of the merit that one can obtain an entire three-dimensional wave field from the data recorded on a two-dimensional surface, the holographic method has been widely studied. Being an experimental method, holography has an unavoidable error which is generate by sampling in space and frequency domain and finite aperture size. Its magnitude is dependent on the space and frequency domain and finite aperture size. Its magnitude is dependent on the shape of hologram surface, acoustic holography may be classified into four types of holography : rectangular type planeholography, circular type plane holography, cylindrical holography and spherical holography. In this paper, four types of holography are studied by modal summation method. Numerical simulation is performed using a monopole source with varying parameters to find out effects to the estimation error in each holography. Experiments of circular type plane holography and cylindrical holography explain strong relation between the shape of hologram surface and the acoustic field.

• Korean Journal of Optics and Photonics
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• v.14 no.2
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• pp.200-207
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• 2003

In this paper we present a new method of measuring the relative distance of two point objects in three-dimensional space by using phase-shifting digital holography. In our system the reference beam of a spherical wave is used instead of a plane wave. The system is computer simulated and built on an optical table for experiments. It is shown from computer simulations and experiments that the relative distance can be measured without the exact information on the reference beam used in the hologram record. It is shown from experiments that the relative distance between two point objects separated by 0.5 cm in the distance of about 300 cm from the CCD can be measured with an error less than 10％.