TY - CONF
AB - This paper experimentally investigates and interprets the e®ects of noise and non-
linearity in a silicon photonic optical test structure. For the analysis di®erent optoelectronic phase
noise measurement techniques are used. Our tests focuses on the performance of integrated opti-
cal test structures using femtosecond pulses in the 1550nm spectral range. A primary objective
is to understand the behaviour of silicon photonic waveguides that can be further employed in the
implementation of an optoelectronic phase-locked loop (OEPLL) in silicon photonics technology.
A comparison of our results, as well as a discussion on the di®erent optoelectronic phase noise
measurement techniques are presented. Our ¯ndings provide insights that can be leveraged to
optimize the design and performance of ultra-low phase noise on-chip OEPLL systems locking
to mode-locked laser (MLL) signals. In the future such systems can be essential for advanced
communication and sensing applications.
AU - Surendranath Shroff, Vijayalakshmi
AU - Kress, Christian
AU - Bahmanian, Meysam
AU - Scheytt, J. Christoph
ID - 47521
T2 - 2023 PhotonIcs & Electromagnetics Research Symposium (PIERS),
TI - Analysis of Phase Noise in Waveguide-integrated Optical Test Structures in Silicon Photonics
ER -
TY - JOUR
AU - Kürpick, Christian
AU - Rasor, Anja
AU - Scholtysik, Michel
AU - Kühn, Arno
AU - Koldewey, Christian
AU - Dumitrescu, Roman
ID - 47420
JF - Procedia CIRP
KW - General Medicine
SN - 2212-8271
TI - An Integrative View of the Transformations towards Sustainability and Digitalization: The Case for a Dual Transformation
VL - 119
ER -
TY - JOUR
AU - Zhai, Xiaokun
AU - Ma, Xuekai
AU - Gao, Ying
AU - Xing, Chunzi
AU - Gao, Meini
AU - Dai, Haitao
AU - Wang, Xiao
AU - Pan, Anlian
AU - Schumacher, Stefan
AU - Gao, Tingge
ID - 40274
IS - 13
JF - Physical Review Letters
TI - Electrically controlling vortices in a neutral exciton polariton condensate at room temperature
VL - 131
ER -
TY - GEN
AU - Sehlmeyer, Birte
AU - Kampmann, Rebecca
AU - Scheidemann, Claus
AU - Hemsel, Tobias
AU - Getzlaff, Mathias
ID - 47234
T2 - Frühjahrstagung 2023, Sektion Kondensierte Materie (SKM)
TI - Burst Mode of Ultrasonic Resonant Oscillations for Stimulation and Destruction of Tumor Cells
ER -
TY - GEN
AU - Kampmann, Rebecca
AU - Sehlmeyer, Birte
AU - Scheidemann, Claus
AU - Hemsel, Tobias
AU - Getzlaff, Mathias
ID - 47235
T2 - Frühjahrstagung 2023, Sektion Kondensierte Marterie (SKM)
TI - Burst Mode Characteristics of an Ultrasonic Transducer for Treatment of Cancer Cells
ER -
TY - GEN
AB - In planar microcavities, the transverse-electric and transverse-magnetic
(TE-TM) mode splitting of cavity photons arises due to their different
penetration into the Bragg mirrors and can result in optical spin-orbit
coupling (SOC). In this work, we find that in a liquid crystal (LC) microcavity
filled with perovskite microplates, the pronounced TE-TM splitting gives rise
to a strong SOC that leads to the spatial instability of microcavity polariton
condensates under single-shot excitation. Spatially varying hole burning and
mode competition occurs between polarization components leading to different
condensate profiles from shot to shot. The single-shot polariton condensates
become stable when the SOC vanishes as the TE and TM modes are spectrally well
separated from each other, which can be achieved by application of an electric
field to our LC microcavity with electrically tunable anisotropy. Our findings
are well reproduced and traced back to their physical origin by our detailed
numerical simulations. With the electrical manipulation our work reveals how
the shot-to-shot spatial instability of spatial polariton profiles can be
engineered in anisotropic microcavities at room temperature, which will benefit
the development of stable polariton-based optoeletronic and light-emitting
devices.
AU - Gao, Ying
AU - Ma, Xuekai
AU - Zhai, Xiaokun
AU - Xing, Chunzi
AU - Gao, Meini
AU - Dai, Haitao
AU - Wu, Hao
AU - Liu, Tong
AU - Ren, Yuan
AU - Wang, Xiao
AU - Pan, Anlian
AU - Hu, Wei
AU - Schumacher, Stefan
AU - Gao, Tingge
ID - 47532
T2 - arXiv:2305.01368
TI - Single-shot spatial instability and electric control of polariton
condensates at room temperature
ER -
TY - GEN
AB - The control and active manipulation of spin-orbit coupling (SOC) in photonic
systems is fundamental in the development of modern spin optics and topological
photonic devices. Here, we demonstrate the control of an artificial
Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a
microcavity filled with an organic single-crystal of photochromic phase-change
character. Splitting of the circular polarization components of the optical
modes induced by photonic RD SOC is observed experimentally in momentum space.
By applying an ultraviolet light beam, we control the spatial molecular
orientation through a photochemical reaction and with that we control the
energies of the photonic modes. This way we realize a reversible conversion of
spin-splitting of the optical modes with different energies, leading to an
optically controlled switching between circularly and linearly polarized
emission from our device. Our strategy of in situ and reversible engineering of
SOC induced by a light field provides a promising approach to actively design
and manipulate synthetic gauge fields towards future on-chip integration in
photonics and topological photonic devices.
AU - Liang, Qian
AU - Ma, Xuekai
AU - Ren, Jiahuan
AU - Long, Teng
AU - Gu, Chunling
AU - An, Cunbin
AU - Fu, Hongbing
AU - Schumacher, Stefan
AU - Liao, Qing
ID - 47533
T2 - arXiv:2309.07652
TI - Photochemical reaction enabling the engineering of photonic spin-orbit
coupling in organic-crystal optical microcavities
ER -
TY - GEN
AB - Topological states have been widely investigated in different types of
systems and lattices. In the present work, we report on topological edge states
in double-wave (DW) chains, which can be described by a generalized
Aubry-Andr\'e-Harper (AAH) model. For the specific system of a
driven-dissipative exciton polariton system we show that in such potential
chains, different types of edge states can form. For resonant optical
excitation, we further find that the optical nonlinearity leads to a
multistability of different edge states. This includes topologically protected
edge states evolved directly from individual linear eigenstates as well as
additional edge states that originate from nonlinearity-induced localization of
bulk states. Extending the system into two dimensions (2D) by stacking
horizontal DW chains in the vertical direction, we also create 2D multi-wave
lattices. In such 2D lattices multiple Su-Schrieffer-Heeger (SSH) chains appear
along the vertical direction. The combination of DW chains in the horizontal
and SSH chains in the vertical direction then results in the formation of
higher-order topological insulator corner states.
AU - Schneider, Tobias
AU - Gao, Wenlong
AU - Zentgraf, Thomas
AU - Schumacher, Stefan
AU - Ma, Xuekai
ID - 47531
T2 - arXiv:2303.12593
TI - Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates
ER -
TY - GEN
AB - Exceptional points (EPs) with their intriguing spectral topology have
attracted considerable attention in a broad range of physical systems, with
potential sensing applications driving much of the present research in this
field. Here we theoretically demonstrate the realization of EPs in a system
with significant nonlinearity, a non-equilibrium exciton-polariton condensate.
With the possibility to control loss and gain and nonlinearity by optical
means, this system allows for a comprehensive analysis of the interplay of
nonlinearities (Kerr-type and saturable gain) and non-Hermiticity. Not only do
we find that EPs can be intentionally shifted in parameter space by the
saturable gain, we also observe intriguing rotations and intersections of
Riemann surfaces, and find nonlinearity-enhanced sensing capabilities. Our
results are quite general in nature and illustrate the potential of tailoring
spectral topology and related phenomena in non-Hermitian systems by
nonlinearity.
AU - Wingenbach, Jan
AU - Schumacher, Stefan
AU - Ma, Xuekai
ID - 47529
T2 - arXiv:2305.04855
TI - Tweaking Spectral Topology and Exceptional Points by Nonlinearity in
Non-Hermitian Polariton Systems
ER -
TY - JOUR
AB - AbstractEfforts to enhance sustainability in all areas of life are increasing worldwide. In the field of manufacturing technology, a wide variety of approaches are being used to improve both resource and energy efficiency. Efficiency as well as sustainability can be improved by creating a circular economy or through energy-efficient recycling processes. As part of the interdisciplinary research group "Light—Efficient—Mobile" investigations on the energy-efficient friction-induced recycling process have been carried out at the department of Forming and Machining Technology at Paderborn University. E.g. using the friction-induced recycling process, different formless solid aluminum materials can be direct recycled into semi-finished products in an energy-efficient manner. The results of investigations with regard to the influence of the geometrical shape and filling rate of the aluminum particles to be recycled as well as the rotational speed of the continuously rotating wheel are explained in this paper. In addition to the recycling of aluminum chips, aluminum particles like powders from the field of additive manufacturing are processed. Based on these results, the future potentials of solid-state recycling processes and their contribution to the circular economy are discussed. The main focus here is on future interdisciplinary research projects to achieve circularity in the manufacturing of user-individual semi-finished products as well as the possibility to selectively adjust the product properties with the continuous recycling process.
AU - Borgert, Thomas
AU - Milaege, Dennis
AU - Schweizer, Swetlana
AU - Homberg, Werner
AU - Schaper, Mirko
AU - Tröster, Thomas
ID - 47536
IS - 6
JF - International Journal of Material Forming
KW - General Materials Science
SN - 1960-6206
TI - Potentials of a friction-induced recycling process to improve resource and energy efficiency in manufacturing technology
VL - 16
ER -