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Transmissive metasurfaces formed by high-index dielectric materials have received great attention due to its potential in holograms, deflectors, beam converters, and flat lenses. However, a key challenge of all-dielectric metasurfaces is the limited scale and high cost in fabrication, such as electron beam lithography (EBL) and focused ion beam (FIB) lithography. In this paper, for the first time to our knowledge, an anodized aluminum oxide (AAO) template is combined with titanium dioxide (TiO2) metasurface fabrication with advantages of large area (>2cm2) and low cost. Using the ordered anodized aluminum oxide (AAO) as an evaporation mask, a TiO2 nanocylinder array is deposited through the AAO mask onto the SiO2 substrate. Electric and magnetic dipole resonances of TiO2 metasurface appear in the visible spectrum. Furthermore, we demonstrate the interaction of the CsPbBr1.5I1.5 quantum dot (QD) emission with magnetic dipole (MD) resonance of TiO2 metasurface. Our results reveal that the metasurface exhibits remarkable photoluminescence (PL) enhancement of 25%. Up to now, a TiO2 metasurface with 2.25-cm2-large area using AAO template method has never been attempted. Different from the metasurfaces fabricated by FIB and EBL, our method offers great ease for large-area metasurface fabrication, which is convenient for metasurface researchers and avoids costly facilities.A record-long 10,118-km fiber transmission with physical layer encryption is demonstrated utilizing a Y-00 cipher based on signal masking by quantum (shot) noise. The Y-00 cipher enables symmetric-key data encryption to ensure the security of the physical layer of optical communications. Irreducible secrecy without significant negative impact on transmission performance is achieved by the synergistic effect of combining seed-key-based high-order modulation and truly random shot noise inevitable in optical detection. This paper reports a comprehensive study of applying a phase-shift-keying (PSK) Y-00 cipher for ultra-long haul fiber transmission. Theoretical analysis shows that security-enhanced transmission over transoceanic-distance (>10,000 km) fiber is feasible when the quadrature PSK data signal is encrypted by converting to a PSK signal with 218 levels. Subsequently, 10,118-km standard single-mode fiber transmission of 48-Gbit/s line-rate dual-polarization PSK Y-00 cipher with 218 levels is experimentally demonstrated. An adequate signal quality above the Q-factor threshold of soft decision forward error correction is achieved together with sufficient signal masking by shot noise, yielding balanced transmission performance and high security in an ultra-long-haul PSK Y-00 cipher transmission system.Mueller matrix ellipsometry has been used to precisely characterize quartz waveplates for demanding applications in the semiconductor industry and high precision polarimetry. We have found this experimental technique to be beneficial to use because it enables us to obtain absolute and precise measurement of retardation in a wide spectral range, waveplate orientation, and compound waveplate adjustment. In this paper, the necessity of including the optical activity in the Mueller matrix model and data treatment is demonstrated. Particularly, the optical activity of the quartz influences the adjustment of misalignment between the perpendicularly oriented waveplates of the compound biplate. We demonstrate that omitting the optical activity from the model leads to inaccurate values of the misalignment. In addition, the depolarization effects caused by a finite monochromator bandwidth is included in the model. Incorporation of the optical activity to the Mueller matrix model has required a development of rigorous theory based on appropriate constitutive equations. The generalized Yeh's matrix algebra to bianisotropic media has been used for the calculation of the eigenmodes propagation in chiral materials with reduced symmetry. Based on the applied method, the authors have proposed approximated analytical form of the Mueller matrix representing optically active waveplate and biplate and provided discussion on the analytical and numerical limits of the method.We present tunable waveguide-based optical parametric amplification by four-wave mixing (FWM) in silicon nitride waveguides, with the potential to be set up as an all-integrated device, for narrowband coherent anti-Stokes Raman scattering (CARS) imaging. Signal and idler pulses are generated via FWM with only 3 nJ pump pulse energy and stimulated by using only 4 mW of a continuous-wave seed source, resulting in a 35 dB enhancement of the idler spectral power density in comparison to spontaneous FWM. By using waveguides with different widths and tuning the wavelength of the signal wave seed, idler wavelengths covering the spectral region from 1.1 µm up to 1.6 µm can be generated. The versatility of the chip-based FWM light source is demonstrated by acquiring CARS images.This study proposes a digital implementation of the conventional Mirage, which uses two parabolic mirrors to produce 360-degree three-dimensional (3D) images of real objects placed inside of it. The two mirrors are replaced with multiple light field displays to generate rays emitted from 3D objects in 360 degrees. We propose two techniques for eliminating repeated 3D images produced by the multiple displays, that is, non-tracking and tracking techniques. The former supports multiple viewers, although the 3D image size is limited. The latter can produce large 3D images, although the number of viewers is limited. The display system of the lower half of the light field Mirage was constructed by using four light field displays to verify the proposed techniques.We present the spatial and temporal characterization of the copper (Cu) plasma produced by the femtosecond laser filaments. The filaments of various lengths and intensities were generated with the aid of three different focusing lenses. Further, the filamentation induced breakdown spectroscopy (FIBS) measurements were carried out for each filament at three different positions along the length of the filament. The filaments were spatially characterized by estimating the plasma temperature and electron density. Our investigation has demonstrated that the centre of the filament is the best to obtain a maximum signal. Both the spectral line intensity and their persistence time are highest for the center of the filament. The enhanced persistence and the scalability of the spectral line intensity tested across different focusing geometries can boost the application of this technique in various fields.We develop a transient photoinduced Kerr rotation spectroscopy technique using a heterodyne detection scheme to study spin dynamics of microscopic quantum states in solids, such as single quantum dots and spin helixes. The use of the heterodyne beat note signal generated by the interference of the frequency-shifted probe and reference pulses realizes the Kerr rotation measurements in combination with micro-spectroscopy, even when the probe pulse propagates collinearly with the strong pump pulse, which resonantly excites the probing state. In addition, the interference gives an optical amplification of the Kerr signal, which provides a clear observation of the photoinduced spin dynamics by the weak probe intensity. Here, we present results of Kerr rotation measurements for a single quantum dot exciton, which shows a maximum rotation angle of few µrad.In this work, a novel all-dielectric metasurface made of arrayed circular slots etched in a silicon layer is proposed and theoretically investigated. The structure is designed to support both Mie-type multipolar resonances and symmetry-protected bound states in the continuum (BIC). Specifically, the metasurface consists of interrupted circular slots, following the paradigm of complementary split-ring resonators. This configuration allows both silicon-on-glass and free-standing metasurfaces and the arc length of the split-rings provides an extra tuning parameter. Imatinib cost The nature of both BIC and non-BIC resonances supported by the metasurface is investigated by employing the Cartesian multipole decomposition technique. Thanks to the non-radiating nature of the quasi-BIC resonance, extremely high Q-factor responses are calculated, both by fitting the simulated transmittance spectra to an extended Fano model and by an eigenfrequency analysis. Furthermore, the effect of optical losses in silicon on quenching the achievable Q-factor values is discussed. The metasurface features a simple bulk geometry and sub-wavelength dimensions. This novel device, its high Q-factors, and strong energy confinement open new avenues of research on light-matter interactions in view of new applications in non-linear devices, biological sensors, and optical communications.The external bandwidth of germanium waveguide photodetectors (PDs) decreases with the device length due to the load and parasitic effects even if the internal one is less affected. Shortening PDs raises the external bandwidth but lowers the responsivity, introducing a trade-off between the two figures of merits. Here, we present a scheme of waveguide PDs based on total internal reflections of corner reflectors. The reflector can be easily fabricated with the standard photolithography at the end of PDs to efficiently reflect optical power back to germanium for additional absorption, allowing for further size reduction. The structure may render the optimization of PDs more flexible.The rapid oscillation of galvanometric resonant optical scanners introduces linear astigmatism that degrades transverse resolution, and in confocal systems, also reduces signal [V. Akondi et al., Optica 7, 1506, 2020]. Here, we demonstrate correction of this aberration by tilting reflective or refractive optical elements for a single vergence or a vergence range, with and without the use of an adaptive wavefront corrector such as a deformable mirror. The approach, based on nodal aberration theory, can generate any desired third order aberration that results from tilting or decentering optical surfaces.The attenuation (sum of absorption and scattering), which is caused by the dense and non-uniform medium, generally leads to problems of color degradation and detail loss in underwater imaging. In this study, we describe an underwater image enhancement method based on adaptive attenuation-curve prior. This method uses color channel transfer (CCT) to preprocess the underwater images, light smoothing, and wavelength-dependent attenuation to estimate water light and obtain the attenuation ratio between color channels, and estimates and refines the initial relative transmission of the channel. Additionally, the method calculates the attenuation factor and saturation constraints of the three color channels and generates an adjusted reverse saturation map (ARSM) to address uneven light intensity, after which the image is restored through water light and transmission estimation. Furthermore, we applied white balance fusion globally guided image filtering (G-GIF) technology to achieve color enhancement and edge detail preservation in the underwater images. Comparison experiments showed that the proposed method obtained better color and de-hazing effects, as well as clearer edge details, relative to current methods.