Multimode laser emission generally takes place in homogeneously broadened gain media placed inside a standing-wave resonator due to spatial hole burning. Solutions proposed to eliminate this phenomenon have so far involved the use of intracavity elements, such as an etalon, wave plates or saturable absorbers. We propose a monolithic solution, wherein birefringent layers of TiO2 are deposited on both laser mirrors. This solution enables one to control the contrast of the interference pattern of the standing wave inside the resonator, and thus the strength of the spatial hole burning, by rotating one mirror around the optical axis. A monochromatic laser emission is demonstrated in a quasi-continuous-wave laser-diode-pumped Yb3+YAG laser experiment.We present the optical and structural characterization of films of Ta2O5, Sc2O3, and Sc2O3 doped Ta2O5 with a cation ratio around 0.1 grown by reactive sputtering. The addition of Sc2O3 as a dopant induces the formation of tantalum suboxide due to the "oxygen getter" property of scandium. The presence of tantalum suboxide greatly affects the optical properties of the coating, resulting in higher absorption loss at λ=1064nm.  https://www.selleckchem.com/products/jsh-23.html  The refractive index and optical band gap of the mixed film do not correspond to those of a mixture of Ta2O5 and Sc2O3, given the profound structural modifications induced by the dopant.Many existing well-known multilayer design methods are based on so-called greedy algorithms. New deep search algorithms developed for needle optimization, gradual evolution, and design cleaner methods are presented. The algorithms possess machine learning features. The advantages of the deep search methods are demonstrated on a set of examples including the OIC Design Contest 2019.Application of electric field and moderately elevated temperature depletes the side facing anode from alkali present in glasses. The change of composition of the treated glass results in variation of refractive index depth profile within the treated glass. Spectroscopic ellipsometry is employed for characterization of optical properties of glass treated in different conditions. The results of optical characterization are verified by secondary ion mass spectroscopy. It is found that the refractive index profile obtained from ellipsometry has a maximum value higher than the one of untreated glass. The obtained refractive index profiles are in very good agreement with concentration profiles.Through the introduction of a broadband (∼1µm) high-efficiency (average above 90%) half-wave plate in the near-infrared (NIR) region, reflective Pancharatnam-Berry metasurfaces that can generate high-intensity (above 90%) left-circular polarization (LCP) and right-circular polarization (RCP) light for broadband (∼900nm) are designed. It provides a method to generate broadband high-efficiency circularly polarized (CP) light, which is a rare complex process in traditional chiroptical spectroscopy. To further show the broadband high-efficiency function of the meta-atom, a broadband high-efficiency reflective vortex beam generator based on metasurfaces is designed for RCP light in the NIR region. Moreover, with the appropriate arrangement, the metasurfaces are able to focus the vortex beam into a point to increase the intensity of the generated vortex beam.Nanostructured low-index layers are useful as the last layers of antireflective (AR) coatings because they can broaden their spectral ranges and improve the performance for oblique light incidence. Structuring of evaporated organic layers by plasma opens a route to produce inorganic interference stacks and low-index layers in the same vacuum process. The organic material uracil has been investigated as a template material for AR nanostructures. An additional plasma-treatment step was added to the manufacturing process, which decreases the organic fraction of the coating substantially. As a result, a better environmental stability and higher transmission in the ultraviolet range was achieved.Surface deformation by coating stress is compensated by prefiguring the substrate with a radially nonuniform layer of dense silica. Stresses in the compensation layer and reflector are modeled using finite element analysis to determine the optimal thickness profile, with the deposited coating reducing the surface deformation by 90%. This process is intended to allow implementation of both the compensation layer and the traditional multilayer coating in a single vacuum cycle.A nitridated Ru/B4C multilayer with period of 3.0 nm and 80 bilayers were fabricated to study thermal and temporal stability. The multilayer was annealed from room temperature to 490°C, and the in situ X-ray measurements showed that the reflectivity remains mostly unchanged up to 300°C. An essential drop of the reflectivity occurred at 490°C with significantly increased interface roughness. A new layered structure with larger thickness than the original multilayer started to appear at 400°C. The nitridated Ru/B4C multilayer remains intact after two years of storage in air, which demonstrated a very good temporal stability.Thin films of Ge, ZnS, YbF3, and LaF3 produced using e-beam evaporation on ZnSe and Ge substrates were characterized in the range of 0.4-12 µm. It was found that the Sellmeier model provides the best fit for refractive indices of ZnSe substrate, ZnS, and LaF3 films; the Cauchy model provides the best fit for YbF3 film. Optical constants of Ge substrate and Ge film as well as extinction coefficients of ZnS, YbF3, LaF3, and ZnSe substrate are presented in the frame of a non-parametric model. For the extinction coefficient of ZnS, the exponential model is applicable. Stresses in Ge, ZnS, YbF3, and LaF3 were estimated equal to (-50)MPa, (-400)MPa, 140 MPa, and 380 MPa, respectively. The surface roughness does not exceed 5 nm for all films and substrates.For the seventh Manufacturing Problem Contest, participants were challenged to fabricate an optical filter with transmittance specified for s-polarization at two incident angles 10° and 50° from 400 nm to 1100 nm. The problem required that contestants be equally versed in the design, deposition, and measurement of optical filters in order to achieve good results. Eight teams from five different countries participated in the contest using various deposition techniques. The fabricated filters had a total thickness between 8.2 µm and 17.6 µm and a total number of layers from 74 to 255, which were deposited onto one or both sides of the substrate. The performances of the filters were measured by two independent laboratories. The evaluation results were presented at the Topical Meeting on Optical Interference Coatings conference held in Santa Ana Pueblo, New Mexico, in June 2019.