Since 2018, the Haiyang-1C/D (HY-1C/D) satellites' Ultraviolet Imager (UVI) has been providing ultraviolet (UV) data for the purpose of detecting marine oil spills. Despite some preliminary understanding of the scaling effects of UV remote sensing, a deeper investigation is needed into the practical application of medium-resolution spaceborne UV sensors in oil spill detection, especially the effect of sunglint. The following aspects meticulously scrutinize the performance of the UVI in this study: visual characteristics of oils within sunglint, the conditions imposed by sunglint for space-based UV detection of oils, and the steadiness of the UVI signal. Sunglint reflections in UVI images are crucial in defining the visual features of spilled oils, as they boost the contrast between the oils and the surrounding seawater. Hepatic progenitor cells Beyond this, the required sunglint intensity for space-based UV detection has been estimated to be in the range of 10⁻³ to 10⁻⁴ sr⁻¹, exceeding those seen within the VNIR wavelengths. Furthermore, the UVI signal's unpredictability enables the demarcation of oil from seawater. The UVI's capabilities, as demonstrated by the data presented above, are confirmed, along with the crucial role of sunglint in satellite-based UV detection of marine oil spills. This provides a new frame of reference for future spaceborne UV remote sensing efforts.

We consider the vectorial extension of the recently developed matrix theory for the correlation between intensity fluctuations (CIF) of the scattered field generated by a collection of particles of $mathcal L$ types [Y. D.M. Zhao and Ding, focusing on optical systems. 30,46460, 2022 was given as the expression. Within the spherical polar coordinate framework, a closed-form connection is established between the normalized complex-valued induced field (CIF) of the scattered electromagnetic wave and the pair-potential matrix (PPM), the pair-structure matrix (PSM), and the spectral degree of polarization (P) of the incident electromagnetic field. Based on this, we pay much attention to the dependence of the normalized CIF of the scattered field on $mathcal P$. It is found that the normalized CIF can be monotonically increasing or be nonmonotonic with $mathcal P$ in the region [0, 1], determined by the polar angle and the azimuthal angle . Also, the distributions of the normalized CIF with $mathcal P$ at polar angles and azimuthal angles are greatly different. These findings are interpreted mathematically and physically, potentially of interest to related fields, specifically those where the role of the CIF of the electromagnetic scattered field is significant.

The hardware architecture of the CASSI (coded aperture snapshot spectral imaging) system, driven by a coded mask pattern, produces a spatial resolution that is not optimal. Given the need to resolve high-resolution hyperspectral imaging, we propose a self-supervised framework based on a physical optical imaging model and a jointly optimized mathematical model. This paper introduces a parallel joint optimization architecture, utilizing a dual-camera setup. This framework's optimization mathematical model, integrated with a physical representation of the optical system, extracts maximum benefit from the color camera's spatial detail information. For high-resolution hyperspectral image reconstruction, the system's online self-learning capacity offers an alternative to the dependence on training datasets of supervised learning neural network methods.

Measurements of mechanical properties in biomedical sensing and imaging applications are now significantly enhanced with the recent advent of Brillouin microscopy as a powerful tool. Faster and more accurate measurements are anticipated through the implementation of impulsive stimulated Brillouin scattering (ISBS) microscopy, eliminating the need for stable narrow-band lasers and thermally-drifting etalon-based spectrometers. However, the degree to which ISBS-based signals exhibit high spectral resolution has yet to be investigated in significant detail. This document examines the ISBS spectral profile, varying with the spatial layout of the pump beam, along with the implementation of new methods for accurate spectral analysis. The pump-beam diameter's enlargement was demonstrably correlated with a steady reduction in the ISBS linewidth. These findings facilitate improved spectral resolution measurements, enabling broader applications of ISBS microscopy.

The significant potential of reflection reduction metasurfaces (RRMs) in the realm of stealth technology is driving considerable research effort. Nonetheless, the standard RRM framework is predominantly developed employing a trial-and-error approach; this method, while practical, is inherently time-consuming and thereby impedes efficiency. A deep-learning-based approach to designing a broadband resource management (RRM) system is presented here. Employing a forward prediction network, we achieve millisecond-speed forecasting of metasurface polarization conversion ratios (PCRs), demonstrating superior efficiency compared to conventional simulation tools. Oppositely, we construct an inverse network that permits the immediate determination of structural parameters based on a supplied target PCR spectrum. Consequently, a methodology for designing intelligent broadband polarization converters has been formulated. Broadband RRM is realized when polarization conversion units are configured in a 0/1 chessboard pattern. Analysis of the experimental results reveals a relative bandwidth of 116% (reflection less than -10dB) and 1074% (reflection less than -15dB), signifying a significant improvement in bandwidth compared to previous iterations.

Compact spectrometers are instrumental in the non-destructive and point-of-care spectral analysis procedure. A VIS-NIR microspectrometer, consisting of a single pixel and a MEMS diffraction grating, is reported here. The SPM's structure contains the components of slits, an electrothermally rotated diffraction grating, a spherical mirror, and the photodiode. Collimating the incident beam, the spherical mirror achieves a precise focus onto the exit slit. Spectral signals, dispersed by the electrothermally rotating diffraction grating, are measured by a photodiode. Encompassing a spectral range from 405 to 810 nanometers with an average spectral resolution of 22 nanometers, the SPM was completely packaged inside a volume of 17 cubic centimeters. This optical module offers a platform for mobile spectroscopic applications including healthcare monitoring, product screening, and non-destructive inspection.

A compact fiber-optic temperature sensor with hybrid interferometers, which benefited from the harmonic Vernier effect, was proposed, realizing a 369-fold enhancement of the Fabry-Perot interferometer (FPI) sensing sensitivity. The sensor's interferometric setup is hybrid, combining a FPI interferometer and a Michelson interferometer. The proposed sensor's construction involves a splicing of the hole-assisted suspended-core fiber (HASCF) to a composite fiber of a multi-mode fiber and a single-mode fiber that are previously fused. The air channel within the HASCF is then filled with polydimethylsiloxane (PDMS). A high thermal expansion coefficient in PDMS results in improved temperature sensitivity for the FPI. By leveraging the harmonic Vernier effect, the limitation imposed by the free spectral range on magnification is circumvented through the detection of intersection responses within internal envelopes. This consequently enables secondary sensitization of the traditional Vernier effect. Exhibiting a high sensitivity of -1922nm/C, the sensor integrates features from HASCF, PDMS, and first-order harmonic Vernier effects. click here Not only a design scheme for compact fiber-optic sensors, but also a novel strategy to amplify the optical Vernier effect, is supplied by the proposed sensor.

The creation and implementation of a deformed circular-sided triangular microresonator, connected by a waveguide, is described. Room temperature unidirectional light emission is experimentally confirmed, exhibiting a 38-degree divergence angle in the far-field pattern. An injection current of 12mA results in single-mode lasing emission at a wavelength of 15454 nanometers. A nanoparticle's binding, with a radius of several nanometers or less, induces a substantial shift in the emission pattern, promising applications in electrically pumped, cost-effective, portable, and highly sensitive far-field detection of nanoparticles.

The significance of Mueller polarimetry, swiftly and precisely operating in low-light fields, lies in its application to the diagnosis of living biological tissues. The acquisition of the Mueller matrix in low-light scenarios is challenging, primarily because of the complicating factor of background noise. multilevel mediation Employing a zero-order vortex quarter-wave retarder, a spatially modulated Mueller polarimeter (SMMP) is first demonstrated. This innovative approach achieves rapid Mueller matrix determination using only four images, a substantial advancement compared to the 16 images necessary in existing methodologies. A momentum gradient ascent algorithm is proposed to efficiently accelerate the reconstruction process of the Mueller matrix. Subsequently, a novel hard thresholding filter, adaptive in its nature, leveraging the spatial distribution characteristics of photons under different low-light conditions, alongside a fast Fourier transform low-pass filter, is utilized for the removal of extraneous background noise from raw low-intensity distributions. The robustness of the proposed method against noise, as highlighted by experimental results, surpasses that of the classical dual-rotating retarder Mueller polarimetry approach by almost an order of magnitude in terms of precision, particularly in low-light conditions.

A design for a novel, modified Gires-Tournois interferometer (MGTI) is reported, particularly suited for high-dispersive mirrors (HDMs). The MGTI framework integrates multi-G-T and conjugate cavities, resulting in substantial dispersion across a broad frequency range. This starting MGTI design results in the production of a pair of highly dispersive mirrors (positive PHDM and negative NHDM). These mirrors provide group delay dispersions of +1000 fs² and -1000 fs² within the 750nm to 850nm spectral span. The theoretical capabilities of both HDMs to stretch and compress pulses are studied by simulating the pulse envelopes reflected from the HDMs. The excellent matching between the positive and negative high-definition modes is confirmed by the production of a near Fourier Transform Limited pulse after fifty reflections on each of the HDMs. Besides, the laser-induced damage performance of the HDMs is evaluated through the application of 800 nanometer, 40 femtosecond laser pulses.