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In this study, we introduce the concept and construction of an innovative Digital Miniature Cathode Ray Magnetometer designed for the precise detection of magnetic fields. This device addresses several limitations inherent to magnetic probes such as D.C. offset, nonlinearity, temperature drift, sensor aging, and the need for frequent recalibration, while capable of operating in a wide range of magnetic fields. The core principle of this device involves the utilization of a charged particle beam as the sensitivity medium. The system leverages the interaction of an electron beam with a scintillator material, which then emits visible light that is captured by an imager. The emitted scintillation light is captured by a CMOS sensor. This sensor not only records the scintillation light but also accurately determines the position of the electron beam, providing invaluable spatial information crucial for magnetic field mapping. The key innovation lies in the combination of electron beam projection, CMOS imager scintillation-based detection, and digital image signal processing. By employing this synergy, the magnetometer achieves remarkable accuracy, sensitivity and dynamic range. The precise position registration enabled by the CMOS sensor further enhances the device's utility in capturing complex magnetic field patterns, allowing for 2D field mapping. In this work, the optimization of the probe's performance is tailored for applications related to the characterization of insertion devices in light sources, including undulators. [ABSTRACT FROM AUTHOR]

We have proposed a structural design for a single photon avalanche diode with a low breakdown voltage. This diode is fabricated using Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 μm HV CMOS technology, and it can maintain a high operating excess voltage in an n-on-p design without requiring any additional customized well layers. The n-on-p type device is particularly advantageous for a 3D-stacked backside illuminated structure and offers excellent photon detection capabilities at longer wavelengths. By incorporating a high doping concentration PDD well layer, we can significantly increase the excess bias, resulting in enhanced photon detection probability in the near-infrared wavelength range, all while maintaining a lower voltage due to a reduction in breakdown voltage. This design also leads to power consumption savings. As a result, our designed device is well-suited for consumer applications such as 3D image rendering and LiDAR technology.

The human eye, sensors, and photoreceptors can be damaged if they are submitted to laser beams with high intensities and low divergence. In the military field, an optical sensor can be damaged by pulsed laser radiations when exposed beyond its capacities. In order to have a protection against such threats, passive optical limiting is used. A mix between a reactive oligomer and a monomer, with methacrylate functions, is studied in the present work giving a thermoset matrix. To prevent the monomer evaporation, which results in the formation of bubbles in the final material, related to the reaction exotherm, an oligomer and a monomer with a high boiling temperature are used as precursors, giving a good alternative to a thermoplastic matrix like polymethyl methacrylate (PMMA). We report the experimental results of transient thermally induced optical nonlinearities (i.e., nonlinear refraction) in methacrylate‐based polymer filters at a nanosecond timescale, focus will be made to compare third order nonlinear refractive index from thermally induced refractive index. Optical filters are obtained by chemical bulk processes. In the present work, both thermoplastics and thermosets matrices were synthesized in order to characterize their optical limiting properties by mean of an appropriate custom‐made optical setup as well as their nonlinear refractive indices measured by the z‐scan technique. Optical measurements in the nonlinear regime are achieved at the wavelength of 1064 nm. To the best of the authors' knowledge, such a work dealing on 3D‐network methacrylate‐based host has never been published. [ABSTRACT FROM AUTHOR]

Microlens array combined with CMOS sensors have recently been the subject of intensive research due to their ability to significantly enhance imaging sensitivity. However, existing microlens arrays suffer from a limited field-of-view, necessitating complex lens assemblies that increase system cost, size and weight. In this study, we present a novel approach utilizing a single layer metalens array composed of low loss and high-index α-Si materials. The metalens array was designed using a phase compensation method to efficiently focus conical light with arbitrary cone angles onto the center pixels of the CMOS sensor. Theoretical analysis demonstrates that the metalens is capable of focusing ± 20° conical light with an impressive efficiency of 83.6 %, which can be extended to arbitrary cone angles. Experimental results reveal a measured focusing efficiency of 73 % under an incidence angle of ± 8.3° for conical light, representing an improvement of 8 % compared to parallel light incidence. This research presents a promising solution for wide-field-of-view metalens arrays in integrated CMOS imaging systems.

Monolithic pixel detectors combine readout electronics and sensor in a single entity of silicon, which simplifies the production procedure and lowers the material budget compared to conventional hybrid pixel detector concepts. Benefiting from the advances in commercial CMOS processes towards large biasing voltage capabilities and the increasing availability of high-resistivity substrates, depleted monolithic active pixel sensors (DMAPS) can cope with the high-rate and high-radiation environments faced in modern high-energy physics experiments. TJ-Monopix2 is the latest iteration of a DMAPS development line designed in 180 nm TowerSemicondutor technology, which features a large scale (2 × 2) cm2 chip divided into (512 × 512) pixels with a pitch of (33 × 33) µm2. All in-pixel electronics are separated from its small collection electrode and process modifications are implemented to improve charge collection efficiency especially after irradiation. The latest laboratory measurements and investigations of a periodic variation in the threshold response relative to the hit arrival time observed for TJ-Monopix2 in typical operating conditions are presented. [ABSTRACT FROM AUTHOR]

Silicon Photomultipliers (SiPMs) are state-of-the-art photon detectors used in particle physics, medical imaging, and beyond. They are sensitive to individual photons in the optical wavelength regime and achieve time resolutions of a few tens of picoseconds, which makes them interesting candidates for timing detectors in tracking systems for particle physics experiments. The Geiger discharges triggered in the sensitive elements of a SiPM, Single-Photon Avalanche Diodes (SPADs), yield signal amplitudes independent of the energy deposited by a photon or ionizing particle. This intrinsically digital nature of the signal motivates its digitization already on SPAD level. A digital SiPM (dSiPM) was designed at Deutsches Elektronen Synchrotron (DESY), combining a SPAD array with embedded CMOS circuitry for on-chip signal processing. A key feature of the DESY dSiPM is its capability to provide hit-position information on pixel level, and one hit time stamp per quadrant at a 3 MHz readout-frame rate. The pixels comprise four SPADs and have a pitch of about 70 μm. The four time stamps are provided by 12 bit Time-to-Digital Converters (TDCs) with a resolution better than 100 ps. The chip was characterized in the laboratory to determine dark count rate, breakdown voltage, and TDC characteristics. Test-beam measurements are analyzed to assess the DESY dSiPMs performance in the context of a 4D-tracking applications. The results demonstrate a spatial hit resolution on a pixel level, a minimum-ionizing particle detection efficiency of about 30 % and a time resolution in the order of 50 ps. [ABSTRACT FROM AUTHOR]

• We provided discussions on the research of CMOS sensors, and the method to enhance the focusing efficiency of photo-sensitive pixels. • Conical light field can be compensated by using a concave lens phase while employing convex metalens phase distribution for parallel beams. • Our metalens design have potential application in integration of the metalens with CMOS sensors. Microlens array combined with CMOS sensors have recently been the subject of intensive research due to their ability to significantly enhance imaging sensitivity. However, existing microlens arrays suffer from a limited field-of-view, necessitating complex lens assemblies that increase system cost, size and weight. In this study, we present a novel approach utilizing a single layer metalens array composed of low loss and high-index α-Si materials. The metalens array was designed using a phase compensation method to efficiently focus conical light with arbitrary cone angles onto the center pixels of the CMOS sensor. Theoretical analysis demonstrates that the metalens is capable of focusing ± 20° conical light with an impressive efficiency of 83.6 %, which can be extended to arbitrary cone angles. Experimental results reveal a measured focusing efficiency of 73 % under an incidence angle of ± 8.3° for conical light, representing an improvement of 8 % compared to parallel light incidence. This research presents a promising solution for wide-field-of-view metalens arrays in integrated CMOS imaging systems. [ABSTRACT FROM AUTHOR]