Our work presents a novel workflow that bridges simulations at the quantum-level of molecular material properties with optical simulations at the device-level. By employing time-dependent density functional theory to characterize individual molecules in terms of their polarizabilities and first-order hyperpolarizabilities, we integrate this data into optical simulations of macroscopic optical devices grounded in scattering theory that, nevertheless, preserve information on the properties of individual molecules. Our novel approach enables the exploration of complex photonic devices made from molecules. We illustrate our methodology with three pertinent problems: (i) Second harmonic generation in thin films of molecular crystalline Urea. (ii) Surface second harmonic response from centrosymmetric 7,9-Dibromobenzo[h]quinolin-10-ol, where only the broken symmetry at the interface induces a second-order nonlinear process. (iii) SHG-CD from BINOL molecules. Our approach addresses the need for comprehensive theoretical descriptions of nonlinear light-matter interactions in complex molecular photonic devices, providing a valuable tool for applications in various fields.

Traditional optimization of lens material uses a two dimensional continuous space to describe a material along with a local optimizer like Levenberg-Marquardt. However other algorithms may be more suited for harder problems, in particular if the problem has several local minima, large number of variables and integer variables. The presented optimization method make use of evolution strategy with covariance matrix adaptation (CMA-ES). A modified version of this algorithm is used to handle the optimization of lens material as integer variables. Results will be focused on the performance obtained with complex camera lens composed of 31 diopters and optimized for 3 configurations corresponding to 3 different f number

Freeform dielectric waveguides connect optical chips made of different materials in fully integrated photonic devices. With a spatial extent in the order of hundred micrometers, they constitute a computational challenge and make Maxwell full-wave solvers unhandy for the accelerated design. Therefore, we need tools for the fast prediction of waveguide transmission to enable the rapid optimization of waveguide trajectories. Previously developed methods relied on the assumption that only a fundamental mode propagates in the waveguide. However, the propagation of higher-order modes is not just unavoidable due to the geometry of the waveguides but also, sometimes, beneficial as it increases the number of channels to transmit information. We present approximation methods for the fast calculation of transmission that accommodates the presence of higher-order waveguide modes. We also show the application of the approximation methods to optimize waveguide trajectories given their input and output ports, and the obstacles to be avoided.

We present a novel approach involving spatially resolved Fourier transform spectroscopy (FTS) combined with diffractive shear interferometry (DSI) prior to ptychographic measurements, in which a pair of HHG pulses with varying time delay is used in a ptychography scan. Through this scheme, we vastly increase wavelength diversity, improving multi-wavelength reconstructions.

Ptychography with multiplexed data is, although feasible, a challenging task if there is a lack of diversity in the measured diffraction patterns. A practical way to improve diversity is through structuring the incident light field. However, there is no metric that quantifies the influence of beam structuring in ptychography. In this work, we propose the use of Jensen Shannon divergence (JSD) as a metric of the diversity in the diffraction patterns that a structured beam can provide between scan positions or between monochromatic contributions in a multi-wavelength HHG beam. We compare the JSD of different types of beams (Gaussian, structured and OAM) illuminating a standard binary USAF resolution target with the achieved resolution of the object under similar experimental conditions. The findings of this comparison indicate that multi-wavelength beams that provide a higher JSD lead to more robust reconstructions and higher object resolution.

Multi-photon polymerization (MPP) is widely recognised as promising approach for the fabrication of fully 3D micro- or nano-metric structures, occurring for example in 3D optical metasurfaces. However, increases in fabrication speed by parallelizing the write process are required to facilitate industrial scale application. We present our work on the adaptation of a photolithography simulator, Dr LITHO, to model the DOE and SLM parallelised MPP process in a novel photoplotter currently developed in the EU Fabulous project, including the calibration of key simulator parameters using feedback from the parallel MPP fabrication of different test structures.

Retrieving the complex refractive index is important to infer chemical and structural properties of a specimen. Ellipsometry is the standard method to measure the refractive index. However, imaging an object with spatially varying refractive index with ellipsometry is difficult. Here, we use ptychography, which is a lensless imaging technique, to image the complex refractive indices of a multi-layer specimen. In our setup, we use a weakly focused laser beam to scan across a specimen. At each scan position, a coherent diffraction from the illuminated area on the specimen is captured with a camera. The diffraction patterns are used to reconstruct both the probe and the reflectivities of the specimen. To retrieve the refractive indices, we define a physical model that describes the reflection in the sample plane and use automatic differentiation to solve for the refractive indices. In contrast to ellipsometry, we also acquire the spatial phase change, which forms a strong constraint in the model, increasing the accuracy of the refractive index reconstructions. Finally, we provide an estimate of the uncertainty on the retrieved refractive indices using monte-carlo simulations.

It is a well understood fact, that geometrical optics constitutes a subset of physical optics. However, this theoretical understanding has not materialized in practical concepts and most optics software products. In practical work of optical engineers and most optics textbooks, physical optics and geometrical optics are discussed without delving into the strong connection of both disciplines. We present a way to formulate physical optics propagation in homogeneous media which enables a seamless transition to the subset of geometrical optics in theory and practice. The resulting algorithm applies solely mathematical quantities to decide about a seamless inclusion of diffraction in an otherwise fully physical optics model.

In many simulations of large optical systems, the requirement on CPU-time and memory renders a simulation of the full system very time consuming or even impossible. A possible solution is the simulation of subsystems and the subsequent stitching of the calculated fields. In distributed computing, stitching may strongly decrease the computation time and the simulation of large systems may become possible. We investigated simulation time and accuracy of the simulations of such systems using the Fourier modal method. For that purpose, we investigated the calculated fields for different boundary conditions and different illuminations by the incident light. For the boundary conditions, we used periodic and absorbing boundaries. The investigated illuminations contain the field that illuminates the full system and restrictions of the illumination to parts of the subsystem. Both points have a significant influence on how large the overlap needs to be to get a desired accuracy.

The modeling of the propagation of light through curved smooth surfaces constitutes the backbone of optical system modeling. The Local Plane Interface Approximation (LPIA) has been suggested for this task and shows excellent accuracy and simulation speed. It assumes a local plane wave and a local plane interface and applies the S matrix solution for stratified media locally. As a physical-optics generalization of ray optics the LPIA technique has been formulated in the space domain. We show that it must be applied in the k-domain to genuinely include effects like the Goos Hänchen shift and, more importantly, lateral shifts due to transmission and reflection at smooth surfaces with coatings. Such shifts lead to small aberrations, which must be included in high-accuracy optical system modeling, e.g., in lithography.

Simulating diffraction of light by volume gratings leads to several problems. The large periodicities in lateral direction and the large number of repetitions of the lattice in perpendicular direction. For thick hologram gratings that are at the Bragg condition, Herwig Kogelnik developed a theory that uses two diffraction orders. We showed that his theory is equivalent to a calculation with the Fourier Modal Method (FMM) restricted to two diffraction orders. In contrast to Kogelnik’s theory the approximated FMM allows for a gradually increase of the accuracy by taking more diffraction orders into account if they are needed for accuracy. This allows for a simulation of gratings with large lateral period. For the large number of repetitions of the lattice in perpendicular direction, we calculate the scattering matrix of one repetition. From this matrix, we calculate the total scattering matrix for the actual number of repetitions in the grating.

We introduce Chromatix: an easy to use, open-source, differentiable wave optics simulation library. Engineered to fully exploit parallelism, from single CPU and GPU workstations to servers with multiple GPUs, Chromatix removes the computational scaling barrier for differentiable wave optics simulations. Chromatix allows for designing and optimizing a wide range of optical systems (e.g., tomography, light field microscopy, and ptychography) as well as solving inverse problems. We expect Chromatix to democratize and power the exploration of a rich design space in computational optics.

We introduce a novel method for maximum-likelihood estimation in ptychography to address the challenge posed by mixed Poisson-Gaussian noise statistics. By integrating a loss function that accounts for both noise sources in computational image retrieval, our approach significantly improves image reconstruction quality under low signal-to-noise ratio conditions. Experimental and numerical data confirm the advantage of our method over traditional approaches that consider only Poissonian noise. This advancement promises enhanced performance in computational imaging applications, particularly in situations where accurate noise modeling is crucial.

The image quality of super multi-view 3D display is affected by the chromatic aberration. Currently, the simulation methods for super multi-view 3D display are based on the theory of geometric optics to trace rays and obtain the numerical simulation results. However, the phenomenon of light dispersion is neglected in geometric optics, which approximates the cylindrical lens as a series of pinhole structures, resulting in inaccurate and biased simulation results. In this paper, we propose a numerical simulation method based on the diffraction theory of wave optics for super multi-view 3D display. The cause of chromatic aberration is analyzed. Moreover, the reverse simulation is performed to calculate the ideal viewpoint composite image without chromatic aberration. The numerical simulation is conducted to verify the feasibility of the proposed method. It is proved that the proposed method simulates the physical propagation process of super multi-view 3D display and improves the reconstructed image quality. In the future, it can be used to achieve the super multi-view 3D light field technology with low crosstalk and large field. This work may pave a new avenue for light filed 3D display, which could lead to applications in virtual reality devices and next-generation display devices such as 3D televisions, telepresence system and 3D display desktop computers.

We present a high-quality factor plasmonic biosensor with a metal-2D material-metal (M-2D-M) structure for dengue detection. The modified prism-based plasmonic sensor consists of two layers of aluminum (Al) (30 nm and 7 nm) sandwiching a layer of 2D nanomaterial (MoS₂). Each layer of the proposed plasmonic device is engineered using the transfer matrix method, considering critical performance parameters such as sensitivity, quality factor, detection accuracy, and Figure of Merit (FOM). The effect of different 2D nanomaterial layers, e.g., antimonene, black phosphorus, graphene, MXene, and molybdenum disulfide (MoS₂), on the sensing parameters is studied in the M-2D-M structure. A monolayer of MoS₂ is considered at the top of the M-2D-M structure as a bio-recognition element to study biomolecular interactions. The final plasmonic multilayer structure, Al-MoS₂-Al-MoS₂, is used for dengue detection by capturing the variation in different blood components, such as plasma, platelets, and hemoglobin, in normal and infected states.