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Publications (55)
For three decades, optical orbital angular momentum (OAM) has been synonymous with phase vortices. Here, our research challenges this paradigm by demonstrating a vortex-free intrinsic OAM arising from three-dimensional caustic trajectories in structured light fields, distinct from traditional vortex-based mechanisms. Optical OAM was traditionally c...
An erratum is given to correct three typographical errors in Optica 11, 531 (2024).OPTIC82334-253610.1364/OPTICA.517474 The corrections do not impact the results and conclusions of the original paper.
We present an innovative approach for the simultaneous agile manipulation of high-refractive-index (HRI) and low-refractive-index (LRI) particles. Our method involves introducing a dual-curvilinear optical vortex beam (DC-OVB) generated by superimposing a pair of curved beams: HRI and LRI particles are controlled by the bright curve and the dark ch...
Since their discovery in the 1990s, vortex beams, known for their ability to carry orbital angular momentum (OAM), have found substantial applications in optical manipulation and high-dimensional classical and quantum information communication. However, their inherent diffraction in free space, resulting in OAM-dependent beam expansion, has constra...
Wavefront distortions pose a significant limitation in various optical applications, hindering further advancements in optical system performance. In this study, a novel generic calibration model based on Zernike‐fitting neural network (ZFNN) is proposed, which enables insitu wavefront correction with just a single‐shot measurement. The experimenta...
Free-space optical (FSO) communication can exploit mode-division multiplexing using orthogonal spatial modes of Laguerre-Gaussian beams, such as orbital angular momentum (OAM) modes, wherein OAM multiplexing offers potentially infinite information capacity due to the arbitrary quantization of OAM. Combined with polarization-division multiplexing an...
Focal field modulation has attracted a lot of interest due to its potential in many applications such as optical tweezers or laser processing, and it has recently been facilitated by spatial light modulators (SLMs) owing to their dynamic modulation abilities. However, capabilities for manipulating focal fields are limited by the space-bandwidth pro...
Structured optical fields embedded with polarization singularities (PSs) have attracted extensive attention due to their capability to retain topological invariance during propagation. Many advances in PS research have been made over the past 20 years in the areas of mathematical description, generation and detection technologies, propagation dynam...
The recognition in the 1990s that vortex beams (VBs), paraxial light beams with optical vortices, carry orbital angular momentum (OAM), has benefited applications ranging from optical manipulation to high-dimensional classical and quantum information communications. The transverse profiles of common VBs, e.g., Laguerre-Gaussian beam and high-order...
The generation and topological configuration of double-layered polarization singularity array (PSA) having paired C-points of opposite topological index through superposing three Laguerre-Gaussian (LG) component beams with orthogonal linear polarization states are demonstrated. The generated PSA beam exhibits diversity in topological geometry and i...
Structured optical fields embedded with polarization singularities (PSs) have attracted extensive attention due to their capability to retain topological invariance during propagation. Many advances in PSs research have been made over the past 20 years in the areas of mathematical description, generation and detection technologies, propagation dyna...
In the fields of optics and photonics, phase-only spatial light modulators (SLMs) play an increasingly important role in wave-front engineering. However, the SLMs are subject to wavefront distortion arising from the imperfection in the birefringence effect and physical structure of modulators. This paper presents a simple self-interference phase ca...
We theoretically propose and experimentally generate the nondiffracting Bessel–Poincaré beams whose Stokes vortices radially accelerate during propagation. To this end, we design the Bessel beams whose intensity is specified to be uniformly distributed along the longitudinal direction. By superposing two such Bessel beams having different helical p...
Owing to the unique feature that the signal and reference waves of self-interference digital holography (SIDH) contain the same spatial information from the same point of object, compared with conventional digital holography, the SIDH has the special spatial coherence properties. We present a statistical optics approach to analyzing the formation o...
We report on a novel curvilinear optical vortex beam named twin curvilinear vortex beams (TCVBs) with intensity and phase distribution along a pair of two- or three-dimensional curves, both of which share the same shape and the same topological charge. The TCVBs also possess the character of perfect optical vortex, namely having a size independent...
Owing to their robustness against diffraction, Bessel beams (BBs) offer special advantages in various applications. To enhance their applicability, we present a method to generate self-accelerating zeroth-order BBs along predefined trajectories with tunable $ z $ direction intensity profiles. The character of tunable $ z $ direction intensity profi...
Carbon capture and storage (CCS) has the potential to play an important role in managing global warming in the near future. Herein, we define the entire energy cycle from energy production to utilization considering energy-environment technologies and describe the technical classification and brief technical principles of CCS technology. In additio...
Sensors are already part of everyday life, and they are based on a mechanical and electronic pattern such as what humans see, hear and do, and they have a wide range of uses and a wide variety of types. The material that forms a sensor and its structure are very important to perform the sensing role. Electrochemical method is a kind of technology t...
We propose a vectorial optical field generation system based on two-dimensional blazed grating to high-efficiently generate structured optical fields with prescribed amplitude, phase, and polarization. In this system, an optimized blazed grating hologram is written on a spatial light modulator (SLM) and can diffract the majority of the incident lig...
Recently, better understanding of nano-area is required for 5 nm or less technology node. In particular, the high contact resistance generated in a nano-area significantly degrades the device performance. In this study, we propose a direct contact resistance measurement method without a test structure by separate processes to improve the nano-area...
There is an urgent need for in situ methods for detecting environmental pollution quickly and accurately. With the development of nanotechnology, a huge potential has been created for the design of highly sensitive sensors with low energy consumption and low costs. If a composite material constructed with carbon nanotubes is used as an electrode in...
Flexible conductive materials exhibit high potentials for application as conductor interconnects for many critical devices. In this study, we report on the optimization of silver interconnections on graphene oxide (GO)-reduced graphene oxide (rGO) substrates by electroless plating (ELP) for the preparation of flexible selective patterned conductive...
We demonstrate that the carbon nanotube (CNT)-graphene contact resistance can be improved by the introduction of an interposer layer and its surface treatment in order to improve the interfacing between vertical CNT interconnects and horizontal graphene lines. To this end, a method to measure the rear-end contact resistance over a nano-sized area w...
Ultra-high-definition (UHD) spatial light modulators (SLMs) enhance the degree of freedom in the versatile engineering of optical field. Among efforts to explore the capability of SLMs, enhancing the efficiency of light utilization is an everlasting quest to find SLM-based applications. We propose a new method to efficiently generate arbitrary vect...
Electrochemical atomic force microscopy is a complex electrochemical analysis method that has been applied in many fields. Electrochemical atomic force microscopy consists of an electrochemical cell, electrochemical analysis system, and atomic force microscopy. To simultaneously analyze the electrochemical system and the atomic force microscopy, an...
In this paper, we present an approach for creating a polarization singularity array (PSA) along a curvilinear structure by exploring a scheme of coaxially superposing pre-designed component vector beams. Each component vector beam independently and azimuthally modulates inhomogeneous polarization distribution based on a combination of holographic b...
The analysis of cleaning solutions is difficult, especially if a chemical reaction occurs in the mixed solution. Such chemical reactions lead to real‐time changes in the vibrations of the molecules due to changes in the binding forces. Thus, techniques for analyzing mixed solutions are required to determine the processes that occur during the clean...
In zirkulierenden Bewässerungssystemen kann es zu einer Anreicherung und Verbreitung von Phytopathogenen kommen. Dies macht phytosanitäre Maßnahmen notwendig. Im Rahmen dessen wurde das System zur elektrolytischen Wasserdesinfektion in Gewächshäusern [SeWiG] entwickelt. Da beim Einsatz dieser Methode unter anderem Chloratanionen als Nebenprodukt en...
Die HU Berlin hat mit der Fa. newtec das System zur elektrolytischen Wasserdesinfektion in Gewächshäusern (SeWiG) entwickelt. Dabei wird vor Ort mittels Elektrolyse aus einer Sole (KCl) eine Desinfektionslösung (KClO) produziert. Diese wird in einem Speichertank bevorratet und bei Bedarf über eine sensorbasierte Dosierung dem Gießwasser bzw. der Nä...
Von der HU Berlin und Fa. newtec wurde das System zur elektrolytischen Wasserdesinfektion in Gewächshäusern (SeWiG) entwickelt. Das bereits im kleinen Versuchsmaßstab erfolgreich getestete Desinfektionssystem wird nun unter Praxisbedingungen auf große Gewächshäuser mit entsprechenden Wasservolumina hoch skaliert und optimiert. In der gärtnerischen...
Von HU und Fa. newtec wurde das System zur elektrolytischen Wasserdesinfektion in Gewächshäusern (SeWiG) entwickelt. Das bereits im kleinen Versuchsmaßstab getestete Desinfektionssystem wird nun unter Praxisbedingungen auf große Gewächshäuser mit entsprechenden Wasservolumina hoch skaliert und optimiert. In der gärtnerischen Praxis besteht vor alle...
Um die Übertragung wasserbürtiger Phytopathogene zu unterbinden, kommt der Desinfektion von Gießwasser bzw. Nährlösung eine zentrale Bedeutung zu.
Das von der Firma newtec und der HU Berlin entwickelte System zur elektrolytischen Wasserdesinfektion in Gewächshäusern (SeWiG) ist wirksam gegenüber einem breiten Spektrum an pflanzlichen Krankheitserre...
An emerging vision for future advances in the modern photonics is to explore the fundamental concepts of light coherently shaped in phase, amplitude, and polarization in different scenarios. In this paper, the conversion between linear and circular polarizations in free space by the beam itself is demonstrated theoretically and experimentally. Any...
We evaluated the selective metal capping layer in a complementary metal-oxide semiconductor image sensor using electroless-deposited CoWP and NiWP films. We investigated the correlation integration issues and the selectivity of the capping layer formed by the electroless plating process. M1M2-R (M1 = Co, Ni, M2 = W, Mo, R = P, B) was selectively de...
Recently, CoWP and CoWB have been applied as metallic-cap materials owing to their electrical conductivity and adhesion with Cu. However, when a metallic cap of CoWP and CoWB is applied, current leakage occurs because of damage caused by the misalignment and over-etching. Therefore, the etch process must be optimized to minimize the damage to the m...
The conversion between different polarizations generally requires an optical element or an optical system. We demonstrate, theoretically and experimentally, that the conversion between different states of polarization (SoP) can be flexibly manipulated in a structured optical field by itself. During the structured optical field propagation in free s...
In this work we discuss the modification of the layer extraction rule (LER) for the elimination of the pattern on shallow trench isolation (STI). The differences in the physical pattering performance between the original LER and the modified LER are investigated with an image sensor device. The minimum design rule of Lightly Doped Drain (LDD) and S...
Recently, with the use high integration and lightweight products, Electromagnetic Interference (EMI) has become a serious problem. Therefore, research on EMI shielding materials is increasing to solve the problem. Metal as EMI shielding materials has excellent properties. However they have problems such as high weight and corrosion. In the paper, w...
We present a method of shaping three-dimensional (3D) vector beams with prescribed intensity distribution and controllable polarization state variation along arbitrary curves in three dimensions. By employing a non-iterative 3D beam-shaping method developed for the scalar field, we use two curved laser beams with mutually orthogonal polarization se...
In this study, we investigated the influence of the reduction temperature on graphene oxide. After performing the thermal reduction at specific temperatures (200, 600, and 1000 °C), the morphological and crystallographic changes were investigated by several analysis methods. The reduced graphene oxides were used as supercapacitor electrodes and ana...
We report the analysis of the radiofrequency (RF) characteristics according to the size, area, and shape of TaN thin-film resistor (TFR) layers. As the TFR size increased, its characteristics were degraded with increasing frequency owing to the increased capacitive parasitic components. As the frequency increased from 1 MHz to 10 GHz, the effective...
Die Minimierung von Chlorat bei der elektrolytischen Gießwasserdesinfektion ist aufgrund problematischer Chloratrückstände in pflanzlichen Lebensmitteln von Bedeutung. Im Hinblick auf verfahrenstechnische Optimierungsvorschläge wurde daher am Beispiel einer Salzelektrolyseanlage (Einkammersystem) geprüft, wie viel Chlorat beim Herstellungsprozess d...
To the background of discussions on problematical residues in plant-derived foods, the procedure for minimising chlorate content in the electrolytic disinfection of irrigation water is of great importance. As a source of adjustment recommendations was investigated, on the basis of a brine electrolysis plant (single chamber system), how much chlorat...
Recently, official food surveillance discovered high residues of chlorate (ClO3 −) and perchlorate (ClO4 −) in different plant-based foods, which was the start of a big discussion in the EU Commission. There is currently no knowledge about possible ClO3 − uptake quantities in vegetable, when hypochlorite (ClO−) is used as a disinfectant in plant pr...
Physical and chemical disinfection methods are used or are under investigation in greenhouse facilities to minimize the occurrence of pathogens and the application of pesticides in recirculating systems. Since the most of these methods differ in their effectiveness, more investigation is needed to produce healthy plants in a sustainable way. Theref...
Der Wiederverwendung von Gießwasser kommt v. a. bei geschlossenen Bewässerungssystemen eine immer größere Bedeutung zu. Ein Problem des rückgeführten Drainwassers ist das Verbreitungsrisiko wasserbürtiger Phytopathogene im Pflanzenbestand. Daher ist ein Verfahren zur pflanzenverträglichen Wasserdesinfektion notwendig, mit dem eine hohe Wirksamkeit...
Wasser kann hinsichtlich seiner Nutzungsart sowie seiner chemischen, physikalischen und mikrobiologischen Parameter sehr unterschiedlich sein. So bestehen Nährlösungen für Hydrokulturen, im Vergleich zum Trinkwasser, aus einer Vielzahl an anorganischen und organischen Substanzen in höherer Konzentration. Dies muss bei der Übertragung der Elektrolys...
Bei geschlossenen Bewässerungssystemen und einer Wiederverwendung des Gießwassers ist das Verbreitungsrisiko von wasserbürtigen Phytopathogenen erhöht. Demnach kommt der Wasserdesinfektion eine besondere Bedeutung zu. Wichtig hierbei ist eine breite Inaktivierung von Pilzen, Bakterien und Viren ohne den Pflanzenbestand negativ zu beeinflussen. Hier...
