Front-End Readout Circuit Design for DEPFET Pixel Detectors in 65-nm CMOS

2026-07-31T10:10:28Z

Front-End Readout Circuit Design for DEPFET Pixel Detectors in 65-nm CMOS Gogolou, Vasiliki; Krüger, Hans; Dingfelder, Jochen This work presents a differential readout integrated circuit for DEPFET pixel matrices, with a systematic evaluation of trade-offs among key performance metrics such as power consumption, noise, and silicon area. Each readout channel integrates a cascode transimpedance amplifier followed by a compact single-ended-to-differential conversion stage, optimized to fully drive the input range of a high-speed, low-power analog- to-digital converter (ADC). The proposed readout architecture is designed in an advanced 65-nm CMOS technology and is designed to interface seamlessly with such ADCs, enabling a system that meets stringent constraints on power density and pixel pitch while delivering the precision required for future high-rate, high-resolution experiments. The circuit targets DEPFET matrices operated in rolling-shutter mode, supporting a minimum input current of 2 µA and a signal range of interest extending up to 8 µA (4 MIPs about 20,000 electrons). The readout operates with a total power consumption of 900 µW per channel and an input-referred noise of 80 nA, corresponding to approximately 200 electrons. The achieved noise performance ensures a comfortable signal-to-noise margin across the full dynamic range.

Strong coupling between WS₂ monolayer excitons and a hybrid plasmon polariton at room temperature

2025-05-30T15:00:30Z

Strong coupling between WS₂ monolayer excitons and a hybrid plasmon polariton at room temperature Zhang, Yuhao; Schill, Hans-Joachim; Irsen, Stephan; Linden, Stefan Light–matter interactions between plasmonic and excitonic modes have attracted considerable interest in recent years. A major challenge in achieving strong coupling is the identification of suitable metallic nanostructures that combine tight field confinement with sufficiently low losses. Here, we report on a room-temperature study on the interaction of tungsten disulfide (WS₂) monolayer excitons with a hybrid plasmon polariton (HPP) mode supported by nanogroove grating structures milled into single-crystalline silver flakes. By engineering the depth of the nanogroove grating, we can change the character of the HPP mode from propagating surface plasmon polariton-like (SPP-like) to localized surface plasmon resonance-like (LSPR-like). Using reflection spectroscopy, we demonstrate strong coupling with a Rabi splitting of 68 meV between the WS₂ monolayer excitons and the lower HPP branch for an optimized nanograting configuration with 60 nm deep nanogrooves. In contrast, only weak coupling between the constituents is observed for shallower and deeper nanogratings since either the field confinement provided by the HPP is not sufficient or the damping is too large. The possibility to balance the field confinement and losses render nanogroove grating structures an attractive platform for future applications.

Physikalisches Institut

Front-End Readout Circuit Design for DEPFET Pixel Detectors in 65-nm CMOS

Strong coupling between WS2 monolayer excitons and a hybrid plasmon polariton at room temperature

Strong coupling between WS₂ monolayer excitons and a hybrid plasmon polariton at room temperature