KiHong Choi

Optical defocus noise suppressing by using a pinhole-polarizer in Fresnel incoherent correlation holography

We propose the method that suppresses the defocus noise optically in the Fresnel incoherent correlation holographic system using a pinhole-polarizer (PP), which is made by punching a pinhole on the linear polarizer. The system configuration of this suggestion is based on the original system with optical-sectioning capability, which is realized by presenting the phase-pinhole on the phase-only spatial light modulator. In our system, the phase-pinhole is replaced with a PP. The replaced component is no longer programmable yet provides an affordable, simple, and light-efficient system configuration. The feasibility of the system with the PP is analyzed and demonstrated.

Achromatic phase shifting self-interference incoherent digital holography using linear polarizer and geometric phase lens

A simple Fresnel-type self-interference incoherent digital holographic recording system is proposed. The main part of the system consists of the two linear polarizers and geometric phase lens. The geometric phase lens is employed as a polarization selective common-path interferometer. One of the polarizers is rotated by the motor and serves as a phase-shifter with the geometric phase lens, to eliminate the bias and twin image noise. A topological phase is obtained by the relative angle between the polarizer and geometric phase lens. Since this phase shifting method does not depend on the change of the optical path length, the phase shifting performance is almost constant in the broad spectral range. Using the proposed achromatic phase shifting method, a simultaneous three-color phase shifting digital hologram recording under the incoherent light source is demonstrated.

Self-interference digital holography with a geometric-phase hologram

Self-interference digital holography (SIDH) is actively studied because the hologram acquisition under the incoherent illumination condition is available. The key component in this system is wavefront modulating optics, which modulates an incoming object wave into two different wavefront curvatures. In this Letter, the geometric-phase hologram lens is introduced in the SIDH system to perform as a polarization-sensitive wavefront modulator and a single-path beam splitter. This special optics has several features, such as high transparency, a modulation efficiency up to 99%, a thinness of a few millimeters, and a flat structure. The demonstration system is devised, and the numerical reconstruction results from an acquired complex hologram are presented.

Analysis of Condition for Integral Floating Display Inducing Proper Accommodation Responses

The condition for the integral floating display is analyzed and evaluated, which elicits the distinguished accommodation responses to different axial locations of targets. The analysis is carried out to derive condition which helps to devise such a system. And measurements of accommodation response from four subjects are conducted to confirm the agreements with the analytical results, by using the auto-refractometer. The two sample Kolmogorov-Smirnov test is applied to evaluate the measurement results qualitatively. The robust agreements between the analysis and the empirical results are observed. This research can be applied in the optimization of augmented reality or virtual reality devices to provide effective three-dimensional depth cues and relieve viewing discomforts.

Optical Sectioning Fresnel-incoherent-holography System With Pinhole-polarizer

The optical sectioning Fresnel incoherent holography (FINCH) system with the pinhole created on the polarizer film is suggested. This combined component can be applied to replace costly and comparably cumbersome optical component equipped to enable optical sectioning capability in FINCH.

Study about change of accommodative responses at the angular resolution boundary of integral floating display

The change of accommodative responses to the integral floating display with regard to the angular resolution boundary which is derived from the integral floating systems, especially by manipulating the floating gap, is assessed and analyzed.