This PDF file contains the front matters associated with SPIE Proceedings Volume 12214, including the Title Page, Copyright information, Table of Contents and Conference Committee list.

The implementation of new methodological possibilities for the creation of images is a transcending aspect of the art sector. In this paper, we present a method for designing and projecting caustic images through optical systems, based on the application of the physical principles of light and inter-disciplinary cooperation. Prior to the experimental work, we conduct literature research to gain a better understanding of the production of caustic images and we conduct a comprehensive literature study to get an understanding of the scientific principles affecting light and how this may be applied to the art world. In addition, we examine comparable approaches created by scientists, engineers, and visual artists, confirming how significant the relationship between artists and scientists has become, especially in recent times. Under this perspective, we set out to explore how caustic images may be generated in an optics laboratory and subsequently included in the design of an immersive installation. The purpose of this study is to exhibit the technique we created for projecting these images on various surfaces. We test multiple variations that can be created in an exhibition area by utilizing light. We can appreciate the opportunity for artistic expression and the creation of fresh knowledge that this method offers.

Direct solar illumination disappears in the umbra when the Moon’s shadow creates a total solar eclipse. However, the sky above an observer in the umbra is not completely dark because of light that scatters into the umbra from the penumbra (partial eclipse region) and beyond. We show that a simple 2nd -order scattering model reproduces the brightness and color within a factor of 2 relative to measurements made with a radiometrically calibrated all-sky imaging system at the total solar eclipse of 21 August 2017 observed in Rexburg, Idaho USA. The model includes a first scattering point outside the umbra and a 2nd scattering point at the center of the umbra that redirects the light downward to the observer. The simulations show that the primary zenith skylight at the center of the umbra arises from light whose first scattering point is near an altitude of 10 km, the first scattering creates an orangish ring of light symmetrically around the horizon up to approximately 10° elevation, and the second scattering creates zenith skylight that is reduced by approximately four orders of magnitude from daylight and that has a slightly higher blue-red ratio than the daylight before and after the eclipse.

Does life exist outside our Solar System? A first step towards searching for life outside our Solar System is detecting life on Earth by using remote sensing applications. One powerful and unambiguous biosignature is the circular polarization resulting from the homochirality of biotic molecules and systems. We aim to investigate the possibility of identifying and characterizing life on Earth by using airborne spectropolarimetric observations from a hot air balloon during our field campaign in Switzerland, May 2022. In this proceeding we present the optical-setup and the data obtained from aerial circular spectropolarimetric measurements of farmland, forests, lakes and urban sites. We make use of the well-calibrated FlyPol instrument that measures the fractionally induced circular polarization (V /I) of (reflected) light with a sensitivity of < 10−4 . The instrument operates in the visible spectrum, ranging from 400 to 900 nm. We demonstrate the possibility to distinguish biotic from abiotic features using circular polarization spectra and additional broadband linear polarization information. We review the performance of our optical-setup and discuss potential improvements. This sets the requirements on how to perform future airborne spectropolarimetric measurements of the Earth’s surface features from several elevations.

Biological structures located at various depths in tissue, such as blood and melanin, are challenging to perceive from digital images acquired with incoherent light sources. Use of cross-polarized light produces a low-coherence signal with latent embedded data. We demonstrate the ability to modulate visible depth of high-resolution digital image data acquired with commercially available equipment. Superficial and deep structures are visualized on a polarization-gated continuum. Conspicuity of chromophores contained in hemoglobin or melanin are increased independently through a color luminance/temperature processing approach. Qualitative visual analysis of structures distributed in skin tissue is achieved by targeting the region where red and green photosite values have equal spectral responsivity, at approximately 580nm, corresponding to a sharp spike in hemoglobin reflectance. This region contains both sufficient quantum efficiency (QE) from red and green color filter channels as well as overlapping melanin and hemoglobin signals from within skin tissue. Leveraging this overlapping tissue signal and sensor QE in the orange (580nm) region, luminance is increased or decreased according to the structure of interest. Shifting the illuminant light's properties from high to low frequencies using Kelvin temperature, polarized light is gated, allowing observation of skin structures at distinct depths. For example, superficial skin layers are separately visualized from deeper vessels or pigment. The novel viewing process may be considered independent component analysis of diffuse reflectance polarization-based optical images, or as low-coherent backscatter imaging of spatial encoded skin features on a spectral continuum. The technique has implications for an array of dermatological and tissue imaging applications.

In the presence of astigmatism, the three-dimensional distribution of rays in the image region passes through two orthogonal lines, the vertical sagittal foci and the horizontal tangential foci. With increasing astigmatic behaviour of the imaging system, the sagittal and tangential foci will be farther removed from each other and the separation between these two planesserves as the measure of astigmatism. Midway between these planes, i.e., corresponding to the defocus term, 𝑊20 = − 𝑊22⁄2 , where 𝑊22 is the co-efficient of astigmatism, the intensity spread is found to be minimum and the transverse plane passing through this point is referred to as the plane of minimum aberration variance. For a diffraction-limited imaging system, the IPSF on this plane is the Airy pattern. In our study, each sector of the azimuthal Walsh aperture is masked by suitably oriented linear polarizers. The polarization phase introduced is a function of the state of polarization (SOP) of the input beam, the transmission axis of orientation of the masking polarizer and the orientation of the analyzer. A feasible method to assess the degree of astigmatic compensation is to compute the IPSF at the plane of minimum astigmatic variance and compare the intensity distribution with that of airy pattern. IPSFs for different values of 𝑊22 are computed with the presence of compensating polarization masked azimuthal Walsh filters at 0° and 90° with input beam parameters a=b=1 , 𝛿 = 90° and analyser kept at a particular angle. The results are compared with IPSFs computed for an unmasked lens and airy pattern.

The authors set the focus in this paper on the description of polarization with the help of the Jones calculus and the application of polarization in photography. Furthermore, the effect of the circular polarization filter is described by using the Jones calculus. Also, an enhancement of artistic and creative possibilities in photography through quantization or parametrization by the Jones matrices is presented.

The photonic nanoarchitectures in the wing scales of butterflies play an important role in the imaginal life of these insects, and they are developed under high evolutionary pressure. These nanocomposites of chitin and air can generate vivid structural colors that are mainly used for sexual communication. In the case of the butterfly species Common Blue (Polyommatus icarus), the nanostructures are reproduced so precisely, that only a ±10 nm peak position variation can be measured in the reflectance spectra of the blue structural color of the wings, which requires nanometer-scale accuracy in the reproduction of the photonic nanoarchitectures. Therefore, these precisely replicated nanoporous structures are promising templates of the future artificial photonic materials and also can be used in the potential applications. In this work, we present the results of our investigations regarding the relationship of the male structural colors with their population genetic structure across the Western Palearctic region. When natural populations were compared to an inbred lineage raised in a custom-made insectarium, variation of the structural color have been discovered which may have genetic background. The population genetic data showed significant differences between the wild European and the inbred lineages while only a minor shift was found in the structural color. This was still in the wavelength range defined by the European populations which is in good agreement with the previous observations that the sexual signaling color is essentially stable over a distance of 1600 km within Europe.

Solar cell absorption efficiencies have in the past been improved by the biomimicry of moth eye nano-patterns. There are however still many optical nanostructures within nature yet to be investigated for solar energy applications. The ‘Glasswing’ Greta Oto butterfly in particular boasts a minimal glare effect of its wings, which is investigated here for benefits to emerging photovoltaic and concentrator photovoltaic designs. Photovoltaic technologies such as thin film and low concentrator systems (stationary optics used to focus light to smaller areas of photovoltaic material) incorporate refractive optical components (including firstly the protective cover glass) and hence require antireflective coatings that optimize transmission. Understanding what aspects of the Glasswing butterflies nanostructured wings allow for their exceptionally low reflectivity opens up a significant resource of energy from new and existing photovoltaic technologies. We have characterized the optical properties of the Glasswing butterfly nanostructures utilizing Scanning Electron Microscope images, Spectrophotometry and measurements of the External Quantum Efficiency Signal of the wings coupled with photovoltaic material.