Optical interference filters (OIFs) are vital components for a wide range of optical and photonic systems. They are pivotal in controlling spectral transmission and reflection upon demand. OIFs rely on optical interference of the incident wave at multilayers, which are fabricated with nanometer precision. Here, we demonstrate that these requirements can be fulfilled by inkjet printing. This versatile technology offers a high degree of freedom in manufacturing, as well as cost-affordable and rapid-prototyping features from the micron to the meter scale. In this work, via rational ink design and formulation, OIFs were fully inkjet printed in ambient conditions. Longpass, shortpass, bandpass, and dichroic OIFs were fabricated, and precise control of the spectral response in OIFs was realized. Subsequently, customized lateral patterning of OIFs by inkjet printing was achieved. Furthermore, upscaling of the printed OIFs to A4 size (29.7 × 21.0 cm²) was demonstrated.

Inductively coupled plasma with an argon/hydrogen (Ar/H₂) mixture is a potential solution to many surface treatment problems, especially when encountering carbon contamination in optical X-ray and extreme ultraviolet instruments. Removing carbon contamination on multilayer thin films with Ar/H₂ plasma extends the lifetime of the above devices. To further investigate the reaction between plasma and carbon, both optical emission spectroscopy and finite element method with multiphysics fields were employed. The results demonstrated that the intensities of the Balmer lines were in good agreement with the densities of the radical hydrogen atoms from the simulation model, showing a dependence on the mixing ratio. At an electrical input power of 165 W and a total pressure of 5 Pa, an optimum mixing ratio of about 35 ± 5 % hydrogen produced the highest density of hydrogen radicals, coinciding with the highest carbon removal rate. This shows that the carbon removal with Ar/H₂ plasma was mainly controlled by the density of hydrogen radicals, and the mixing ratio showed a significant impact on the removal rates.

Mechanoresponsive smart windows have been intensively investigated in recent years as they offer various applications for signage and light management. However, integrating a display functionality into such smart windows remains a challenge since the realization of pixels in these devices is difficult. In addition, mechanoresponsive smart windows with a high dynamic range are rarely demonstrated because they would suffer from complex fabrication processes and high costs. In this work, a novel surface modification process and digital encoding were developed for direct inkjet printing of micro‐etching‐masks on hydrophobic elastomers, and a pixelated haze distribution was realized. Compared to the traditional mechanoresponsive smart windows, which modify the optical performance by applied strain solely, here, a smart window with haze tunability in either static or strain‐applied state is demonstrated. The work enhances the potential of the fabricated smart window to be applied in high dynamic range signage displays.

Wide band-gap resonant converters operating with zero voltage switching (ZVS) recently proved the conversion of up to $25 \,\mathrm{k}\mathrm{W}$ at $3 \,\mathrm{M}\mathrm{Hz}$ with an efficiency of $\approx$$94 \%$. This is of special interest for any application where power in middle frequency range is required since typically achieved efficiencies for those frequencies are in the range of $60\% \hbox{--}70\%$. Inductively coupled plasma (ICP) based applications would significantly benefit from this fact, but they entail special driving challenges. ICP loads exhibit strong impedance variations during ignition and operation, which means a high limitation factor when driving them with resonant converters. This article offers a deeper look into this topic through the example of a $10 \,\mathrm{Pa}$ Xenon lamp. The ignition transient is measured and analyzed while driving the system with a Silicon Carbide (SiC)-based resonant converter. An FEM simulation modeling the electromagnetic, thermal, mechanical, and plasma properties is also performed. The results are contrasted with the corresponding measurements showing as well the simulation usefulness as a design tool. Theoretical calculations of the intrinsic limits for ZVS resonant power conversion are also offered. This provides an insight into which analysis and control methods would make ICP loads compatible with these converters and, therefore, able to benefit completely from their efficiency and power density benefits.

In this paper, an efficient inductively coupled medium pressure source for ultraviolet radiation (UV-source) is demonstrated. The lamp was operated with powers up to 3 kW while the radiation and the coldest point temperature were measured. In addition, different coil geometries were investigated. Here a symmetrical and asymmetrical winding density were compared. Also the operation pressures and DC to radiation efficiencies are presented. In this work, an operation pressure of one atmosphere and an UV-efficiency (200–380 nm) of 15.5% was achieved. This is comparable to conventional medium pressure Hg-lamp technology. The main advantage of the presented inductive lamp is the electrodeless operation and therefore the longer service life, since an electrode failure is eliminated.

Inductive plasma discharge has been a part of continuous investigations since it was discovered. Especially the E- to H-mode transition and the hysteresis behavior have been topics of research in the last few decades. In this paper, we demonstrate a way to reduce the hysteresis behavior by the usage of a microwave ignition system. With this system, a significant decrease of the needed coil current for the ignition of the inductive driven plasma is realized. For the microwave generation, a magnetron as in a conventional microwave oven is used, which offers a relatively inexpensive way for microwave ignition aid. At the measured pressure of 7.5 Pa, it was possible to reduce the needed coil current for the inductive mode transition by a factor of 3.75 compared to the mode transition current without the ignition aid. This was achieved by initiating the transition by a few seconds of microwave coupling. The performed simulations suggested that the factor can be further increased at higher pressures. That is especially interesting for plasmas that are hard to ignite or for RF-sources that cannot deliver high enough currents or frequencies for the ignition.