Diffraction Focal Position and Vector Diffraction Theory for Micro Holographic Storage Systems

作者：Min Cheol Ki; Moon Hyungbae; Kim Do Hyung; Park No Cheol^*; Park Kyoung Su; Park Young Pil

来源：Applied Sciences-Basel, 2014, 4(1): 57-65.

DOI：10.3390/app4010057

• microholographic storage system
• diffraction focus
• scalar diffraction theory
• vector diffraction theory
• polarization
• refractive index modulation
• interferogram
• diffraction efficiency

In this study, we proposed a method to determine the optimal focal position for micro-holographic storage systems, using vector diffraction theory; the theory provides exact solutions when the numerical aperture (NA) exceeds 0.6. The best diffraction focus was determined by the position and wavelength corresponding to minimal spherical aberration. The calculated refractive index modulation, polarization illumination, and boundary conditions at the interface of different media were analyzed. From the results of our analysis, we could confirm the size of micrograting as a function of NA and wavelength, based on vector diffraction theory, compared with scalar diffraction theory which defines the micrograting by lambda/(2NA). To demonstrate our analysis, we adapted an optical alignment method using a Twyman-Green interferometer, and could obtain good agreement between analysis and experimental results.

• 出版日期2014-3