• 한국광학회지
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• 제23권1호
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• pp.1-5
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• 2012

근축회절 이론에서는 횡배율이 달라도 파장과 수치구경이 같으면 항상 동일하게 회절한다. 하지만 수치구경이 큰 광학계에서는 비근축 회절효과에 의하여 횡배율에 따라 회절 특성이 변화하게 된다. 이 연구에서는 높은 수치구경을 가지는 무수차 광학계에서 나타나는 비근축 회절효과를 주요면의 만곡이라는 관점에서 해석하고, 배율이 다른 무수차 원추곡면경의 결상에서 비근축회절효과에 의한 MTF의 변화를 살펴보았다.

• 한국광학회지
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• 제25권1호
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• pp.8-13
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• 2014

유한광선추적과 곡선적합을 통하여 높은 개구수를 가지는 대물광학계의 비근축 동함수를 계산하는 방법에 대하여 연구하고, 원적외선용 대물렌즈와 무수차 타원경의 축상 상점의 결상에서 비근축 회절효과에 의한 MTF 저하를 분석하였다. 타원경은 원적외선용 대물렌즈와 동일한 근축 사양을 가지도록 구성되었다.

• Journal of the Optical Society of Korea
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• 제1권2호
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• pp.67-73
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• 1997

Light wave diffraction from multiple superposed volume gratings is inestigated using a perturbative iteration method of the integral equation of Maxwell's wave equation. The host material and index gratings are anisotropic and non-coplanar multiple volume gratings are considered. In this method, the paraxial approximation and lack of backward scattering in conventional coupled mode theory are not assumed. Systematic analysis of anisotropic wave diffraction due to multiple noncoplanar volume index gratings is performed in increasing level of diffraction orders corresponding to successive iterations.

• 비파괴검사학회지
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• 제36권2호
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• pp.112-120
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• 2016

The nonlinearity parameter is frequently measured as a sensitive indicator in damaged material characterization or tissue harmonic imaging. Several previous studies have employed the plane wave solution, and ignored the effects of beam diffraction when measuring the non-linearity parameter ${\beta}$. This paper presents a multi-Gaussian beam approach to explicitly derive diffraction corrections for fundamental and second harmonics under quasilinear and paraxial approximation. Their effects on the nonlinearity parameter estimation demonstrate complicated dependence of ${\beta}$ on the transmitter-receiver geometries, frequency, and propagation distance. The diffraction effects on the non-linearity parameter estimation are important even in the nearfield region. Experiments are performed to show that improved ${\beta}$ values can be obtained by considering the diffraction effects.

• Journal of the Optical Society of Korea
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• 제2권2호
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• pp.58-63
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• 1998

Cross-talk effects in high-density volume holographic interconnections are investigated using perturbative iteration method of the integral form of Maxwell's wave equation. In this method, the paraxial approximation and negligence of backward scattering introduced in conventional coupled mode theory is not assumed. Interaction geometries consisting of non-coplanar light waves and multiple index gratings are studied. Arbitrary light polarization is considered. Systematic analysis of cross-talk effects due to multiple index gratings is performed in increasing level of diffraction orders corresponding to successive iterations. Some numerical examples are given for first and third order diffraction.