arXiv subjects

André Zimmermann

Publications and source records attributed to André Zimmermann.

7 recordsLinked to original sources

arXiv2026

Review of MEMS Transducers for Audio Applications

Microelectromechanical systems (MEMS) speakers are compact, scalable alternatives to traditional voice coil speakers, promising improved sound quality through precise semiconductor manufacturing. This review provides an overview of the research landscape, covering baseband-displacement, ultrasound-based, and thermoacoustic sound generation concepts, classifying MEMS speakers by their actuation principles as electrodynamic, piezoelectric, or electrostatic devices. A comparative analysis of performance indicators from 1990 to 2026 highlights the dominance of piezoelectric MEMS with baseband displacement, focusing on miniaturization and efficiency. The review outlines upcoming research challenges and identifies potential candidates for achieving full-spectrum audio performance. A focus on innovative approaches could lead to widespread adoption of MEMS-only speakers.

eess.AS↗

arXiv2026

Steady-state dynamics of quantum frequency combs in microring resonators

Optical frequency combs are utilized in a wide range of optical applications, including atomic clocks, interferometers, and various sensing technologies. They are often generated via four-wave mixing in chip-integrated microring resonators, a method that requires low optical input power due to the high-quality factor of the resonator, making it highly efficient. While the classical properties of optical frequency combs are well established, this work investigates the quantum-mechanical characteristics of the individual comb modes. We derive closed-form analytical expressions describing the squeezing, second-order correlation and joint spectral intensity between the generated signal and idler modes. This comprehensive theoretical framework enables an intuitive understanding and optimization of the quantum features across the comb, revealing conditions for substantial squeezing and entanglement relevant for quantum information processing. Our findings highlight the profound impact of design and dispersion on these quantum properties and offer a foundational tool for chip-integrated quantum applications, including quantum sensing, computing and communication.

quant-ph↗

arXiv2025

Evaluating LLM-based Workflows for Switched-Mode Power Supply Design

Large language models (LLMs) have great potential to enhance productivity in many disciplines, such as software engineering. However, it is unclear to what extent they can assist in the design process of electronic circuits. This paper focuses on the application of LLMs to switched-mode power supply (SMPS) design for printed circuit boards (PCBs). We present multiple LLM-based workflows that combine reasoning, retrieval-augmented generation (RAG), and a custom toolkit that enables the LLM to interact with SPICE simulations to estimate the impact of circuit modifications. Two benchmark experiments are presented to analyze the performance of LLM-based assistants for different design tasks, including parameter tuning, topology adaption and optimization of SMPS circuits. Experiment results show that SPICE simulation feedback and current LLM advancements, such as reasoning, significantly increase the solve rate on 269 manually created benchmark tasks from 15% to 91%. Furthermore, our analysis reveals that most parameter tuning design tasks can be solved, while limits remain for certain topology adaption tasks. Our experiments offer insights for improving current concepts, for example by adapting text-based circuit representations

cs.AR↗

arXiv2025

Chip-integrated single-mode coherent-squeezed light source using four-wave mixing in microresonators

Squeezed light constitutes a key resource for quantum optical technologies including quantum sensing, computing, communication and metrology. For many applications the generation of squeezed light typically requires at least two nonlinear optical stages involving careful phase and frequency matching to achieve the required mixing of squeezed and coherent light. In our work, we introduce an on-chip system that simplifies the generation of coherent-squeezed light, utilizing only a single squeezing stage. We achieve this by pumping a silicon nitride ($\mathrm{Si_3N_4}$) microring resonator to produce single-mode squeezed light through four-wave mixing at the same frequency as the pump mode, leveraging the inherent $χ^{(3)}$-nonlinearity of the $\mathrm{Si_3N_4}$ resonator. Our on-chip system demonstrates a squeezing of -4.7 dB with a clear perspective towards -10 dB squeezing. We also provide a theoretical model that describes the straightforward yet robust generation of single-mode squeezing at the injection locking point of the ring resonator. In fact, we show that a design with a normal dispersion can be used for robust generation of bright squeezed light without the need for careful suppression of unwanted nonlinear processes. Overall, our findings highlight an approach which drastically simplifies the generation of coherent-squeezed light in photonic integrated circuits.

quant-ph↗

arXiv2025

Nonlinear optical bistability in microring resonators for enhanced phase sensing

Photonic microring resonators are used in a variety of chip-integrated sensing applications where they allow one to measure transmission intensity changes upon external signals with a sensitivity that scales linearly with the Q factor. In this work, we suggest exploiting the nonlinear self-phase-modulation effect to increase the overall sensitivity by an additional gain factor appearing when the operational point of the nonlinear resonator is chosen just at the crossover from the monostable to the bistable regime. We present the theoretical idea together with a first proof of concept experiment displaying a gain factor of 22 on a chip-integrated silicon-nitride resonator.

physics.optics↗

arXiv2024

Optical interferometer using two-mode squeezed light for enhanced chip-integrated quantum metrology

This work discusses the possibility of using two-mode squeezed light to improve the performance of existing sensor technology with the focus on its miniaturization under realistic losses. Therefore, we analyze a system consisting of a part for the two-mode squeezed light generation, a sensor region and a detection stage. Based on a general four-wave mixing (FWM) Hamiltonian caused by the third order susceptibility, we formulate linearized equations that describe the FWM process below the threshold and are used to analyze the squeezing quality between the generated optical signal and idler modes. For a possible realization, the focus is set on the chip-integrated generation using micro-ring resonators. To do so, the impact of the design and the pump light are considered in the derived equations. These equations are used to analyze the usage of two-mode squeezed light in quantum metrology and the application in a Mach-Zehnder interferometer (MZI). Due to the impact of losses in realistic use cases, we show that the main usage is for small and compact devices, which can lead to a quantum improvement up to a factor of ten in comparison of using coherent light only. This enables the use of small squeezing-enhanced sensors with a performance comparable to larger classical sensors.

quant-ph↗

arXiv2020

Parametric Amplification of Broadband Vibrational Energy Harvesters for Energy-Autonomous Sensors Enabled by Field-Induced Striction

We investigate the influence of parametric excitation on MEMS vibration energy harvesters for energy autonomous sensor systems. In Industry 4.0 (or Industrial IoT) applications, interconnected sensors provide a means of data acquisition for automated control of the manufacturing process. Ensuring a continuous energy supply to the sensors is essential for their reliable operation. Manufacturing machines usually display a wide spectrum of vibration frequencies which needs to be covered by an array of harvester substructures in order to maintain the desired output level. We show that mechanical structures designed to implement a Helmholtz-Duffing oscillator have an increased bandwidth by exploiting several orders of parametric resonances. In contrast to concepts implementing parametric amplification in a multi-mode scenario, our concept is based on a single mechanical mode. Therefore, it is more robust against fabrication tolerances as the relevant multi-mode resonance conditions do not need to be matched on the level of single chips. Using exact transient simulations and semi-analytic models to showcase the relation of the Helmholtz-Duffing oscillator to the damped and driven Mathieu equation, we show that parametric resonances highly increase the bandwidth of the output power whenever high Helmholtz nonlinearities are present. To achieve the required nonlinearities, we suggest nonlinear stress-strain curves and we propose to achieve such nonlinearities through field-induced striction by magneto- or electrostriction. Thus, we are able to propose a novel energy harvester concept incorporating strictive materials that exploits the effects of parametric excitation to achieve broadband vibrational energy harvesting.

physics.app-ph↗