Angus, not only an eminent scientist but also a remarkable teacher, mentor, colleague, and friend, deeply impacted the entire thin film optics community.

Participants in the 2022 Manufacturing Problem Contest were given the challenge of producing an optical filter with a specified transmittance that varied in steps across three orders of magnitude, from 400 to 1100 nanometers. Selleckchem 2,4-Thiazolidinedione To achieve satisfactory results, the problem mandated that participants possess expertise in optical filter design, deposition procedures, and accurate measurement techniques. Five institutions supplied a group of nine samples, showing total thicknesses between 59 and 535 meters, with a corresponding layer count variance between 68 and 1743. Independent spectral measurements of the filter were carried out in three different laboratories. The results' presentation at the Optical Interference Coatings Conference in Whistler, B.C., Canada, occurred in June 2022.

Through the process of annealing, amorphous optical coatings exhibit a decrease in optical absorption, scattering, and mechanical loss; an increase in the annealing temperature yields more significant reductions. Maximum permissible temperatures are confined to the levels at which coating defects, such as crystallization, cracking, or bubbling, start to manifest. Post-annealing, static observation reveals coating damage brought about by heating. To understand the temperature dependence of damage during annealing, a dynamic experimental method is needed. Such a method would provide valuable information to optimize manufacturing and annealing processes, thereby enhancing coating performance. An instrument, unique to our knowledge, incorporates an industrial annealing oven with strategically placed side viewports. Real-time, in-situ monitoring of optical samples, their coating scattering, and any emerging damage mechanisms is possible during the annealing process. We report findings that showcase in-situ observation of alterations to titania-doped tantalum coatings on fused silica substrates. Annealing allows for a spatial representation (a mapping) of these changes' evolution, providing a more advantageous method than x-ray diffraction, electron beam, or Raman methods. Considering other experiments in the literature, we conclude that crystallization underlies these observed modifications. We delve further into the applicability of this apparatus for observing other forms of coating damage, including cracking and blistering.

Traditional methods of coating struggle to accommodate the complexities of 3D optical shapes. Selleckchem 2,4-Thiazolidinedione The current research involved modifying large top-open optical glass cubes, measuring 100 mm along each side, so as to effectively simulate the performance of extensive, dome-shaped optics. For the visible range (420-670 nm), antireflection coatings were applied on two demonstrators, whilst atomic layer deposition was used for applying coatings to six demonstrators at a single wavelength (550 nm). Measurements of reflectance on both the inner and outer glass surfaces indicate a conforming anti-reflective (AR) coating, leaving residual reflectance well below 0.3% for visible wavelengths and 0.2% for individual wavelengths across practically the entire surface area of the cubes.

Polarization splitting at oblique incidence interfaces is a major impediment to the proper functioning of optical systems. By overcoating an initial organic structure with silica, followed by the removal of the organic materials, low-index nanostructured silica layers were synthesized. By modifying the nanostructured layers, one can achieve low effective refractive indices, with a minimum value of 105. Homogeneous layers stacked together can produce broadband antireflective coatings with exceptionally low polarization splitting. Thin interlayers separating low-index structured layers proved instrumental in refining polarization properties.

Employing pulsed DC sputter deposition of hydrogenated carbon, we have developed an absorber optical coating showcasing maximized broadband infrared absorptance. An infrared absorptance exceeding 90% across the 25-20 m spectrum, accompanied by decreased infrared reflection, is achieved through the layering of a hydrogenated carbon antireflection coating with low absorptance on top of a broadband-absorbing nonhydrogenated carbon layer. The infrared optical absorptivity of sputter-deposited carbon, which incorporates hydrogen, is diminished. To that end, the optimization of hydrogen flow is elucidated, with the goal of minimizing reflection loss, maximizing broadband absorptance, and establishing a balanced stress. The procedure for applying complementary metal-oxide-semiconductor (CMOS) produced microelectromechanical systems (MEMS) thermopile devices to wafers is described. The model's prediction is verified by the 220% increase in thermopile output voltage.

Microwave plasma-assisted co-sputtering was employed to deposit (T a 2 O 5)1-x (S i O 2)x mixed oxide thin films, and their optical and mechanical properties, along with post-annealing treatments, are characterized in this work. Low mechanical loss materials (310-5) with a high refractive index (193) were deposited, all while controlling processing costs. The observed trends included the following: An elevated SiO2 concentration in the mixture correlated with an increase in the energy band gap, and elevated annealing temperatures correlated with a decrease in the disorder constant. The mixtures' annealing process demonstrated a positive influence on reducing mechanical losses and optical absorption. Using a low-cost process, this highlights their suitability as a substitute high-index material for optical coatings within gravitational wave detectors.

The study effectively highlights the design of dispersive mirrors (DMs), providing important and intriguing outcomes that are relevant to the mid-infrared spectral range from 3 to 18 micrometers. The most important design specifications, encompassing mirror bandwidth and group delay variation, had their acceptable domains mapped and built. Through analysis, the necessary total coating thickness, the thickness of the thickest layer, and the expected number of layers have been ascertained. Upon analyzing several hundred DM design solutions, the results have been verified.

Post-deposition annealing processes induce modifications in the physical and optical properties of coatings fabricated through physical vapor deposition techniques. The index of refraction and spectral transmission of optical coatings are subject to alteration during the annealing procedure. Thickness, density, and stress, among other physical and mechanical properties, are likewise affected by annealing. Our study examines the origin of these modifications by scrutinizing the effect of 150-500°C annealing on N b₂O₅ films prepared through thermal evaporation and reactive magnetron sputtering. Data interpretation, using the Lorentz-Lorenz equation and potential energy models, aligns with observations and clarifies contradictions in prior research.

The 2022 Optical Interference Coating (OIC) Topical Meeting's design challenges encompass reverse-engineering black-box coatings and developing a pair of white-balanced, multi-bandpass filters suitable for three-dimensional cinema projection in both frigid and scorching outdoor settings. Representing a collective effort from 14 designers from China, France, Germany, Japan, Russia, and the United States, 32 designs were submitted in response to design problems A and B. A detailed evaluation of the problems and the presented solutions is included.

We propose a post-production characterization approach using spectral photometry and ellipsometry data derived from a custom-designed collection of samples. Selleckchem 2,4-Thiazolidinedione The final multilayer (ML) sample's precise thickness and refractive index were ascertained by measuring single-layer (SL) and multilayer (ML) sets of samples, the fundamental constituents of the final material, outside the experimental apparatus. Several methods of characterization, utilizing external measurements of the final machine learning sample, were assessed. A comparison of their reliability led to the recommendation of the most practical method, with a focus on scenarios where the preparation of the stated samples proves challenging.

The defect's nodular structure and the laser's angle of incidence significantly impact the spatial distribution of laser light intensification within the nodule, and how laser light is removed from the imperfection. A parametric study investigates nodular defect geometries, unique to ion beam sputtering, ion-assisted deposition, and electron-beam deposition, respectively, considering a wide array of nodular inclusion diameters and layer counts in optical interference mirror coatings. These coatings use quarter-wave thicknesses and are capped with a half-wave thickness of the lower refractive index material. Studies on hafnia (n=19) and silica (n=145) multilayer mirrors deposited using electron beams at various angles found that light intensification within nodular defects, featuring a C factor of 8, was maximized in a 24-layer design. Within nodular defects, the intensification of light was decreased when the layer count for normal-incidence multilayer mirrors was increased, considering inclusion diameters of an intermediate size. A second parametric study considered how the shape of nodules affected the intensification of light, maintaining a constant number of layers. In relation to the different shapes of nodules, a significant temporal trend is present. The draining mechanism of laser energy varies across nodule dimensions; narrow nodules drain predominantly through their base, while wide nodules show a greater drain through their top surface upon normal-incidence irradiation. Employing a 45-degree incidence angle, waveguiding acts as an auxiliary method for expelling laser energy from the nodular defect. In conclusion, laser light lingers longer within the nodular flaws than it does in the nearby defect-free multilayer.

Spectral and imaging systems in modern optics frequently employ diffractive optical elements (DOEs), however, the task of achieving high diffraction efficiency while maintaining a broad working bandwidth is often challenging.