Conference Agenda

In this work, a motionless method to achieve quantitative phase imaging in single-pixel microscopy based on the transport of intensity equation is presented. In this approach, a digital micromirror device is used to generate wide-field structured illumination over the sample. The light resulted by the interaction between the sequence of light patterns and the sample is collected using a bucket detector. The integration of a focus tunable lens allows the motionless acquisition of multiple intensity images required for applying the transport of intensity equation. Quantitative phase retrieval in active single-pixel microscopy is demonstrated by imaging calibrated pure-phase test targets.

Photonic circuits, engineered to couple optical modes according to a specific map, serve as processors for classical and quantum light. They can be employed for tasks like vector-matrix multiplications, unitary transformations, and nonlinear operations, forming the basis for application like quantum computing. Liquid-crystal meta-surfaces (LCMSs) have recently been employed for optical simulations of quantum walks (QWs), by coupling transverse light modes with the polarization degree of freedom. These can be modeled as patterned waveplates, whose optic-axis orientation angle is non-uniform in space. In general, the system’s size and complexity (number of LCMSs) grow with the simulated evolution, affecting its feasibility in quantum experiments due to optical losses. Based on [3], we present an implementation of a purely quantum photonic circuit for a two-photon quantum walk experiment using a spontaneous parametric down-conversion source with visibility > 95%. We perform up to 5-step walks, involving up to 30 modes.

While indirect optical geometry measurements do not rely on the optical characteristics of the target’s surface, they depend on the presence of the fluorescent particles in the surrounding medium. In order to overcome uncertainty limits due to the random particle distribution, a well-controlled single particle is applied using an optical tweezer. As a result, the surface of a transparent object is detected via a trapped silica particle to pave the way for more precise indirect optical geometry measurements and to make measurable what is difficult to measure with state-of-the-art direct optical principles.

This work discusses the full-field measurement and characterization of guided ultrasonic waves (GUWs) on technical surfaces. The measurement is realized by a lensless digital holography approach with stroboscopic coherent illumination. This approach ultimately yields the height distribution featuring the deformation caused by the GUWs, which is then statistically evaluated using the structure function. As a result, GUWs are captured single-shot and characterized regarding wavelength and amplitude.

We propose a precise method for measuring the rotation angle of the polarization plane using a polarization-holographic grating combined with a quarter-wave plate. This approach enables real-time measurements with high accuracy.

To reduce the computational load for Digital Image Correlation (DIC) measurement, this paper proposes a multi-level grid interpolation and motion characteristics analysis initial guess method. In an image, all subsets that need to be calculated are divided into multiple levels of grids. Based on the deformation parameters of low-level grid cells, the initial deformation parameters of higher-level grid cells can be estimated. In the image sequence of quasi-static material tests, the deformation parameters of the 0-level subsets in the next image can be estimated by analyzing the motion characteristics of those subsets. The proposed method is validated using images from the classic "DIC Challenge". The algorithm proposed in this paper can effectively improve the accuracy of overall initial value estimation, and improving the overall execution speed of the algorithm.