This paper presents an effective three-dimensional (3D) surface reconstruction technique aimed at profiling composite surfaces with both specular and diffuse reflectance. Three-dimensional measurements based on fringe projection techniques perform well on diffuse reflective surfaces; however, when the measurement targets contain both specular and diffuse components, the efficiency of fringe projection decreases. To address this issue, the proposed technique integrates digital holography into the fringe projection setup, enabling the simultaneous capture of both specular and diffuse reflected light in the same optical path for full-field surface profilometry. Experimental results demonstrate that this technique effectively detects and accurately reconstructs the 3D profiles of specular and diffuse reflectance, with fringe analysis providing the absolute phase of composite surfaces. The experiments validate the effectiveness of this technique in the 3D surface measurement of integrated circuit carrier boards with chips exhibiting composite surfaces.

This study presents a novel label-free approach for characterizing cell death states, eliminating the need for complex molecular labeling that may yield artificial or ambiguous results due to technical limitations in microscope resolution. The proposed holographic tomography technique offers a label-free avenue for capturing precise three-dimensional (3D) refractive index morphologies of cells and directly analyzing cellular parameters like area, height, volume, and nucleus/cytoplasm ratio within the 3D cellular model. We showcase holographic tomography results illustrating various cell death types and elucidate distinctive refractive index correlations with specific cell morphologies complemented by biochemical assays to verify cell death states. These findings hold promise for advancing in situ single cell state identification and diagnosis applications.

Diffraction calculations, which are fundamental in wave optics, can be significantly accelerated using Fourier transforms. However, they often suffer from ringing artifacts, also known as the Gibbs phenomenon, owing to the discontinuous borders of the calculation windows. Various techniques to suppress ringing artifacts have been proposed, but are typically time-consuming and require additional memory resources. This study proposes a fast method for reducing ringing artifacts using Fresnel integrals without necessitating additional memory. A comparison between the proposed and conventional techniques demonstrates that the proposed method achieves comparable image quality to conventional methods. Moreover, it offers the advantages of fast time and low memory usage. This paper demonstrates that the proposed method can be used to efficiently reduce ringing artifacts in reproduced images of two inline holograms optically acquired with laser and light-emitting diode sources.

This study presents a common-path (CP) digital holographic microscopy (DHM) that employs computer-generated holograms specifically designed for individual imaging conditions. By integrating multi-wavelength operation and varifocal capability, the system can stably record and reconstruct object wavefronts across different wavelengths and varifocal conditions within a CP configuration. The experimental results demonstrate the feasibility and effectiveness of the proposed method, highlighting its robust phase reconstruction performance under various imaging conditions. The system’s practicality is further validated through quantitative phase imaging of white blood cells and microbeads under different wavelength and varifocal settings. The integration of these features significantly enhances the flexibility, stability, and adaptability of CP DHM, paving the way for broader application in high-precision imaging, quantitative phase analysis, and biomedical diagnostics.

Lenses play a critical role in optical systems, where the surface radii of curvature directly affect imaging quality and system performance. Accurate and efficient measurement of both surface curvatures is essential for optical design validation and quality control. This study proposes a non-contact digital holography method based on a combined transmission–reflection configuration for simultaneous measurement of the front and back surface radii of curvature. Using a coaxial optical setup, both transmitted and reflected holograms are captured concurrently. Surface profiles are extracted via numerical reconstruction and curvature fitting. Experiments on plano-convex, bi-convex, and negative meniscus lenses verify that the proposed method reliably measures both surface curvatures with high consistency to nominal design values, demonstrating its accuracy and potential for practical optical inspection.