A5005434073- Photonic and Optical Devices
- Photorefractive and Nonlinear Optics
- Advanced Fiber Laser Technologies
- Semiconductor Quantum Structures and Devices
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Mechanical and Optical Resonators
- Photonic Crystals and Applications
- Optical Network Technologies
- Neural Networks and Reservoir Computing
- Physics of Superconductivity and Magnetism
- Hearing Loss and Rehabilitation
- Congenital Heart Disease Studies
- Semiconductor Lasers and Optical Devices
- Molecular Junctions and Nanostructures
- Optical Wireless Communication Technologies
- Advanced Semiconductor Detectors and Materials
- Energy Load and Power Forecasting
- Ultrasound Imaging and Elastography
- Advanced Optical Sensing Technologies
- Vascular anomalies and interventions
- Spectroscopy and Laser Applications
- Space Satellite Systems and Control
- Magnetic properties of thin films
- Cardiovascular Conditions and Treatments
Paderborn University
2017-2024
University Medical Center Hamburg-Eppendorf
1989-2024
Universität Hamburg
1987-2024
Technische Universität Dresden
2023
Karlsruhe Institute of Technology
2001
Institut für Technische und Angewandte Physik (Germany)
1987
Many technologies in quantum photonics require cryogenic conditions to operate. However, the underlying platform behind active components such as switches, modulators and phase shifters must be compatible with these operating conditions. To address this, we demonstrate an electro-optic polarisation converter for 1550nm light at 0.8K titanium in-diffused lithium niobate waveguides. do so, exploit properties of convert between orthogonal modes a fiber-to-fiber transmission >43%. We achieve...
Interfacing single-photon detectors with active photonic components is a cornerstone quantum technology. We describe how the output signal of commercial superconducting nanowire can be used in situ to drive such as lasers and electro-optic modulators, co-located cryostat. This enabled by developing custom circuitry using cryogenic-compatible discrete SiGe-BiCMOS platform. have demonstrated this number experiments, particular optical readout an SNSPD low-latency feed-forward modulation based...
We study the coupling of Landau levels and electric subbands in quasi-two-dimensional electron inversion layers modulation-doped GaAs/${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Al}}_{\mathrm{x}}$As heterojunctions tilted magnetic fields. employ far-infrared Fourier-transform spectroscopy with light polarized parallel to layers. When subband separation ${E}_{10}$ is much larger than cyclotron energy \ensuremath{\Elzxh}${\ensuremath{\omega}}_{c}$, we find an enhancement mass...
Superconducting detectors are now well-established tools for low-light optics, and in particular quantum boasting high-eciency, fast response low noise. Similarly, lithium niobate is an important platform integrated optics given its high second-order nonlinearity, used high-speed electro-optic modulation polarization conversion, as well frequency conversion sources of light. Combining these technologies addresses the requirements a single capable generating, manipulating measuring light...
Lithium niobate serves as a key quantum photonics integration platform, hosting cryogenic optical devices such SNSPDs and dots. We explore the impact of pyroelectricity in environment lithium waveguides.
Quantum photonic processing via electro-optic components typically requires electronic links across different operation environments, especially when interfacing cryogenic such as superconducting single photon detectors with room-temperature control and readout electronics. However, driving electronics can introduce detrimental parasitic effects. Here we show an all-optical of a nanowire detector (SNSPD), completely electrically decoupled from room temperature We provide the power for...
Abstract Lithium niobate is a promising platform for integrated quantum optics. In this platform, we aim to efficiently manipulate and detect states by combining superconducting single photon detectors modulators. The cryogenic operation of detector dictates the optimisation electro-optic modulators under same operating conditions. To that end, characterise phase modulator, directional coupler, polarisation converter at both ambient temperatures. voltage <mml:math...
Superconducting Nanowire Single Photon Detectors (SNSPDs) have become an integral part of quantum optics in recent years because their high performance single photon detection. We present a method to replace the electrical input by supplying required bias current via photocurrent photodiode situated on cold stage cryostat. Light is guided through optical fiber, which enables lower thermal conduction and galvanic isolation between room temperature stage. show that off-the-shelf InGaAs–InP...
A periodic linear quadratic Gaussian (LQG) control law augmented with a reference point adaption to enable adequate rotor speed tracking and sufficient load reductions for wind turbine is presented. The solution of the LQG problem based on solving two Ricatti differential equations in continuous time multiple shooting integration technique. For this, available gridded time-variant description converted harmonic representation using Fourier approximation. While controller provides effective...
We report a novel photovoltaic response occurring in gated AlAs-GaAs heterojunctions whenever inversion electrons absorb far-infrared radiation at cyclotron resonance. With intensities below 1 mW/${\mathrm{cm}}^{2}$, photovoltages up to several mV are observed with the strongest signals around even Landau-level filling factors. The experiment can be described within framework of carrier heating caused by resonantly absorbed radiation. present simple model demonstrating that photovoltage...
The optical absorption of a single spherical semiconductor quantum dot in an electrical field is studied taking into account the nonlocal coupling between electric light and polarizability semiconductor. These effects lead to small size dependent shift broadening excitonic resonance, which may be interest future precision experiments.
We demonstrate second-harmonic generation in a fiber-coupled periodically poled titanium in-diffused lithium niobate waveguide over the temperatures range from 292 to 4.4 K. observe reproducible shift phase-matched pump wavelength within telecom band, which is at odds with phase matching arising existing models of refractive indices this temperature regime. further investigate transient discontinuities while cycling, we attribute build-up and discharge pyroelectric fields. Our results show...
Lithium niobate has emerged as a promising platform for integrated quantum optics, enabling efficient generation, manipulation, and detection of states light. However, integrating single-photon detectors requires cryogenic operating temperatures, since the best performing are based on narrow superconducting wires. While previous studies have demonstrated operation light sources electro-optic modulators in LiNbO3 at thermal transition between room temperature conditions introduces additional...
Abstract Lithium niobate has emerged as a promising platform for integrated quantum optics, enabling efficient generation, manipulation, and detection of states light. However, integrating single-photon detectors requires cryogenic operating temperatures, since the best performing are based on narrow superconducting wires. While previous studies have demonstrated operation light sources electro-optic modulators in LiNbO 3 at thermal transition between room temperature conditions introduces...
Background: Congenital heart disease (CHD) is the most common birth defect worldwide. Depending on complexity of CHD, around 50% these children require cardiovascular surgery, which may involve removal thymus for a better access to heart. Given pivotal role in shaping functional adaptive immune response, thymectomy have detrimental health consequences.
Background: Congenital heart disease (CHD) is the most common birth defect worldwide, and up to 50% of infants with CHD require cardiovascular surgery early in life. Current clinical practice often involves thymus resection during cardiac surgery, detrimentally affecting T cell immunity. However, epidemiological data indicate that patients face an elevated risk for infections, cancer autoimmune diseases, irrespective thymectomy. Hence, we examined whether impacts function individuals CHD.
Cryogenic opto-electronic interconnects are gaining increasing interest as a means to control and read out cryogenic electronic components. The challenge is achieve sufficient signal integrity with low heat load processing. In this context, we demonstrate the bias readout of commercial four-pixel superconducting nanowire single-photon detector array using photodiode laser. We show that approach has similar system detection efficiency conventional bias. Furthermore, multi-pixel events...
Cryogenic opto-electronic interconnects are gaining increasing interest as a means to control and readout cryogenic electronic components. The challenge is achieve sufficient signal integrity with low heat load processing. In this context, we demonstrate the bias of commercial four-pixel superconducting nanowire single-photon detector array using photodiode laser. We show that approach has similar system detection efficiency conventional bias. Furthermore, multi-pixel events faithfully...
We demonstrate an opto-electronic operation of SNSPD at 1K, utilizing a photodiode bias and cryogenic laser for signal-readout. The photonic link reduces the heatload maintains high performance SNSPD.
Modulation conditioned on measurements entangled photonic quantum states is a cornerstone technology of optical information processing. Performing this task with low latency requires combining single-photon-level detectors both electronic logic processing and modulation in close proximity. In the technologically relevant telecom wavelength band, detection best performed high-efficiency, low-noise, high-speed based photon-induced breakdown superconductivity. Therefore, using these devices for...
We demonstrate an electro-optic polarisation converter for 1550nm at cryo genic temperatures in titanium in-diffused lithium niobate waveguides. The switching voltage increases, the modulation depth remains unchanged, and we show operation up to 25 MHz.