Article
Chemistry, Physical
Yanqiu Zou, Li Jiang, Tengfei Zhai, Tingting You, Xufeng Jing, Rongyang Liu, Fanghao Li, Wei Zhou, Shangzhong Jin
Summary: High-performance enhancement of Raman scattering is achieved through hierarchical CuS microflowers, with enhancement sensitivity proved to be related to the number and spacing of CuS petals and illumination of the incident wavelength. CuS microflowers serve as a high-performance SERS platform to expand the application field of SERS.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Faezeh Mohaghegh, Alireza Mazaheri Tehrani, Arnulf Materny
Summary: The increase in inelastically scattered signal observed in Surface-enhanced Raman spectroscopy (SERS) is attributed to different mechanisms. The study revealed a transition to pure electromagnetic enhancement when molecules are separated from the metal surface. By preventing direct contact between molecules and the metal surface, the electronic (chemical) enhancement mechanism can be switched.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Electrochemistry
Sheila Hernandez, Juan Perales-Rondon, Aranzazu Heras, Alvaro Colina
Summary: EC-SOERS is a new phenomenon that enhances the Raman signal during the oxidation of a metal surface. Studies show that carbonyl and carboxyl groups are necessary to observe this phenomenon, with a delocated charge being important factor. Evaluating the enhancement factors for different molecules with highly delocated charge and a carboxyl group sheds more light on the interaction of molecules with the electrochemically generated SOERS substrates.
ELECTROCHIMICA ACTA
(2021)
Article
Chemistry, Analytical
Ibrahim Halil Oener, Christin David, Christine Joy Querebillo, Inez M. Weidinger, Khoa Hoang Ly
Summary: This study presents a facile approach to determine the electromagnetic field enhancement and optical activity of nanostructured TiN electrodes, using the combination of TiN electrodes and surface-enhanced Raman scattering (SERS) spectroscopy. The results provide valuable insights into the properties and applications of TiN electrodes.
Article
Chemistry, Physical
Yongsong Wang, Fengming Chen, Xiao Guo, Jinxin Liu, Junjie Jiang, Xiaoming Zheng, Zihan Wang, Mansour M. Al-Makeen, Fangping Ouyang, Qinglin Xia, Han Huang
Summary: The systematic Raman investigations on exfoliated b-As flakes revealed the effects of symmetry, excitation wavelength, and flake thickness on their phonon behaviors. The temperature-dependent analysis showed linearly anharmonic behaviors of phonons and a slightly greater first-order temperature coefficient in the zigzag direction. The findings give deep insights into the in-plane phonon anisotropy and anharmonicity of b-As, contributing to future device applications.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Lingyan Meng, Yu Wang, Man Gao, Mengtao Sun
Summary: The study theoretically investigated the electric field gradient effect in the TERS system using the finite element method, quantitatively distinguishing the respective contributions of electric field and electric field gradient to dipole Raman and gradient Raman modes in the TERS spectrum. By comparing the relative intensity ratio between electric field gradient and electric field, the TERS configuration could be optimized to achieve a maximum of gradient Raman modes. Theoretical results reveal the influence of molecular symmetries on molecular hyperpolarizability, which significantly impacts the plasmonic electric field gradient effects, providing useful information for the design of TERS platforms with more spectrum information.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Lei Ouyang, Tobias Meyer-Zedler, Kel-Meng See, Wei-Liang Chen, Fan-Cheng Lin, Denis Akimov, Sadaf Ehtesabi, Martin Richter, Michael Schmitt, Yu-Ming Chang, Stefanie Grafe, Jurgen Popp, Jer-Shing Huang
Summary: This study investigates the enhancement effect of plasmonic gratings in nonlinear surface-enhanced coherent anti-Stokes Raman scattering (SECARS) using the platform of plasmonic Doppler grating (PDG). The PDGs spatially separate the input and output enhancement, allowing for observation and comparison of overall enhancement from different combinations of individual input and output beams. The results indicate that enhancement in the pump and anti-Stokes beams plays a more critical role in the overall enhancement than that in the Stokes beam.
Article
Chemistry, Analytical
Irina A. Boginskaya, Ekaterina A. Slipchenko, Marina V. Sedova, Julia Yu. Zvyagina, Alexander D. Maximov, Aleksandr S. Baburin, Ilya A. Rodionov, Alexander M. Merzlikin, Ilya A. Ryzhikov, Andrey N. Lagarkov
Summary: This study investigates the modifications of myoglobin's microstructure deposited onto SERS-active Ag-based substrates through drying a drop of aqueous solution with and without laser irradiation. The study shows that drying with laser irradiation leads to the formation of various types of protein aggregates, including crystal-like aggregates. Additionally, the SERS spectra of these aggregates exhibit changes in the position of vibration bands and the amplitudes ratios compared to proteins dried without additional treatment. The research establishes a correlation between surface irregularities, the amplitude, and the change in the SERS spectra during the drying process.
Article
Chemistry, Physical
Tamitake Itoh, Yuko S. Yamamoto
Summary: The relationship between the enhancement of optical responses of molecules and plasmon resonance has been investigated using different techniques. Quantum optics predicts that this enhancement is directly related to optical absorption and indirectly related to Rayleigh scattering and extinction. A micro-spectroscopic method is developed to obtain various optical properties and electromagnetic (EM) enhancement in plasmonic systems. The results show that absorption reproduces the EM enhancement better than Rayleigh scattering or extinction, emphasizing the importance of absorption spectroscopy in evaluating EM enhancement in coupled plasmonic systems.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Review
Spectroscopy
Prompong Pienpinijtham, Yasutaka Kitahama, Yukihiro Ozaki
Summary: Tip-enhanced Raman scattering (TERS) is a new nano-vibrational spectroscopy technique that attracts significant interest for obtaining site-specific molecular information. TERS instruments have advanced and expanded applications to various fields like nanomaterials, liquid samples, biological materials, and electrochemistry, offering molecular imaging at subnanometer resolution.
JOURNAL OF RAMAN SPECTROSCOPY
(2021)
Article
Engineering, Electrical & Electronic
Hsien-Chi Lai, Yu-Jui Wang, Chi-An Dai, Chun-Hway Hsueh, Shu-Jen Wang, Jia-Han Li
Summary: The SERS technique combined with photonic nanojets has successfully enhanced the sensitivity of Raman signals, particularly in the detection of plant growth regulator kinetin. It has also shown the capability of measuring ultra-low concentrations of kinetin. Numerical simulations suggest that this technique has considerable potential for various analytes in sensing applications.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Nanoscience & Nanotechnology
Kang Qin, Kai Liu, Sheng Peng, Zongyan Zuo, Xiao He, Jianping Ding, Yanqing Lu, Yongyuan Zhu, Xuejin Zhang
Summary: Recent advances in near-field technology have allowed for further identification of surface-enhanced Raman scattering (SERS) enhancement theories and monitoring of SERS substrates. Using scattering-type scanning near-field optical microscopy, we verified the electromagnetic enhancement mechanism for SERS by studying an array of metal-insulator-metal (MIM) subwavelength structures. Our near-field optical measurements showed that the SERS enhancement factor (EF) varied across the finite array, with additional enhancements observed in periodic arrays and finite arrays with strong coupling effects.
Article
Chemistry, Physical
Ankai Wang, Shengli Zou
Summary: The induced dipole of the central nanoparticle plays a key role in the enhancement factor of the radiative decay rate of emitters. The near-field coupling among multiple emitters will determine the magnitude and phase of the induced dipole of the central nanoparticle. When the magnitude of the induced dipole is much larger than those of the emitting dipoles, a high enhancement factor will be obtained, and the phase of the induced dipole is less important.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Engineering, Environmental
Changmin Park, Dohyun Lim, Seung Mo Kong, Nam-Il Won, Yang Ho Na, Dongha Shin
Summary: This study develops a cost-effective and time-efficient method for detecting nanoplastics, which have received significant attention due to their potential harm to the water environment. The study introduces a substrate that exhibits Surface-enhanced Raman scattering (SERS) activity and allows for the detection of nanoplastics on the substrate using darkfield-based strategy. The technique enables point-by-point detection of single nanoplastics and has universal application in establishing a global map of nanoplastics and advancing our understanding of the environmental life cycle of plastics.
Article
Physics, Applied
Zhe Shen, Xuefei Zi, Mengyuan Du, Lin Zhang, Yaochun Shen, Maohai Hu
Summary: Numerical simulation of the local electric field enhancement in the virtual-real probe dimer structure revealed ultrahigh field enhancement and spatial resolution, making it promising for high-sensitivity detection and high-resolution imaging.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Meguya Ryu, Molong Han, Lina Grineviciute, Jingwen Hu, Tania Moein, Reo Honda, Tomas Katkus, Mark J. Tobin, Jitraporn Vongsvivut, Tomas Tolenis, Yoshiaki Nishijima, Soon Hock Ng, Saulius Juodkazis, Junko Morikawa
Summary: The birefringence analysis of SiO2 films deposited at a glancing angle of 70° on resist pillar arrays and nanopatterned SiO2 substrates is carried out using spectral and color imaging modes. The films can be distinguished based on retardance and birefringence using RGB numerical analysis. By inserting a λ/2 waveplate and rotating the birefringent sample, the range of chromaticity xy-coordinates is increased, facilitating a better determination of birefringence.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Peichao Wu, Xiaowen Cao, Wubo Chu, Zhihao Chen, Hongbing Yuan, Rujia Wang, Songbai Yao, Saulius Juodkazis, Wenwu Zhang
Summary: With the rapid development of micro-optical applications, there is an increasing demand for micro-optical elements that can be made with minimal processing steps. This study reports on the fabrication of diamond Fresnel zone plates (FZPs) by femtosecond laser direct writing, which provide a compact solution for focusing and imaging. The fabricated FZPs showed well-defined geometry and excellent focusing and imaging ability, making them suitable for various potential applications.
Article
Chemistry, Multidisciplinary
Giedrius Balcas, Mangirdas Malinauskas, Maria Farsari, Saulius Juodkazis
Summary: This article provides an overview of a recent advancement in optical 3D printing, where crosslinkable materials and nanomaterial fillers are polymerized and guided to form final structures and new composites through high temperature annealing (HTA). By using ultrafast laser direct writing, 3D nano/micro-structures are defined and their precursor composition is tailored for subsequent tunability of final properties during the HTA process at temperatures between 750-1500 degrees C. This method takes advantage of efficient pyrolysis and calcination, facilitated by the large surface-to-volume ratio conditions, to enable chemical exchange between glass/ceramic and surrounding materials.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jaworski C. C. Capricho, Tzu-Ying Liao, Boon Xian Chai, Ahmed Al-Qatatsheh, Jitraporn (Pimm) Vongsvivut, Peter Kingshott, Saulius Juodkazis, Bronwyn Louise Fox, Nishar Hameed
Summary: This study demonstrates the potential of macroradical epoxies as surface coating materials, with the use of magnets during polymerization. The magnetically oriented and stable radicals in the polymer backbone render the coatings antimicrobial.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Analytical
Haoran Mu, Daniel Smith, Tomas Katkus, Darius Gailevicius, Mangirdas Malinauskas, Yoshiaki Nishijima, Paul R. Stoddart, Dong Ruan, Meguya Ryu, Junko Morikawa, Taras Vasiliev, Valeri Lozovski, Daniel Moraru, Soon Hock Ng, Saulius Juodkazis
Summary: Microlens arrays (MLAs) were fabricated using a femtosecond direct laser write (fs-DLW) technique, allowing high-fidelity definition of 3D surfaces on IR transparent substrates. A graphene oxide (GO) grating acting as a linear polariser was also fabricated by fs-DLW. The MLAs and GO polarisers were characterised and their performance was simulated through numerical modelling with good agreement between experimental results and simulations.
Article
Chemistry, Analytical
Jovan Maksimovic, Haoran Mu, Daniel Smith, Tomas Katkus, Mantas Vaiciulis, Ramunas Aleksiejunas, Gediminas Seniutinas, Soon Hock Ng, Saulius Juodkazis
Summary: Ultra-short 230 fs laser pulses with a wavelength of 515 nm were used to create 0.4-1 μm holes in alumina Al2O3 etch masks with a thickness of 20-50 nm, simplifying the fabrication of high-efficiency solar cells. The conditions of laser ablation and the effects of sub-surface Si modifications were studied through plasma etching, numerical modeling, and minority carrier lifetime measurements. Mask-less patterning of Si using fs laser direct writing for dry plasma etching of Si was proposed.
Review
Physics, Applied
Hamed Arianfard, Saulius Juodkazis, David J. Moss, Jiayang Wu
Summary: Sagnac interference, as a fundamental optical approach, is widely used for reflection manipulation, precision measurements, and spectral engineering. The integration fabrication techniques have enabled chip-scale Sagnac interferometers, which offer advantages in terms of reduced complexity and high stability. This paper reviews the theory, applications, and challenges of functional integrated photonic devices based on Sagnac interference.
APPLIED PHYSICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Eugene G. G. Gamaly, Saulius Juodkazis
Summary: The minimum laser energy required for material removal decreases with decreasing pulse duration in the sub-picosecond range. These short pulses minimize energy losses by being shorter than the electron-to-ion energy transfer and electronic heat conduction times. When the pulse duration is shorter than the ion period, conduction electrons with energy higher than the work function expel ions off the surface, leaving behind a few atomic layers of bare ions. The emission of electrons is followed by the explosion, ablation, and THz radiation of the bare ions. We compare this phenomenon with the classical photo effect and nanocluster Coulomb explosions, discuss the differences, and explore the possibility of experimentally detecting new modes of ablation through emitted THz radiation. We also consider the application of high-precision nano-machining with low-intensity irradiation.
Article
Chemistry, Multidisciplinary
Denver Linklater, Arturas Vailionis, Meguya Ryu, Shuji Kamegaki, Junko Morikawa, Haoran Mu, Daniel Smith, Pegah Maasoumi, Rohan Ford, Tomas Katkus, Sean Blamires, Toshiaki Kondo, Yoshiaki Nishijima, Daniel Moraru, Michael Shribak, Andrea O'Connor, Elena P. Ivanova, Soon Hock Ng, Hideki Masuda, Saulius Juodkazis
Summary: In this article, we provide an overview of structural and optical characterization techniques that are useful for biomaterials. These techniques allow for new insights into the structure of natural fibers, such as spider silk, with minimal sample preparation. By utilizing electromagnetic radiation over a broad range of wavelengths, information about material structure at different length scales can be obtained. Additionally, polarization analysis of optical images can provide further information on feature alignment when optical characterization is not sufficient.
Article
Chemistry, Multidisciplinary
Charitha Weerasuriya, Soon Hock Ng, William Woods, Tom Johnstone, Pranciskus Vitta, Laila Hugrass, Saulius Juodkazis
Summary: Color plays a significant role in human activities and affects the circadian cycle and decision making process. The subjective nature of color perception makes it vital to study human judgment under different colored illuminations. This study developed necessary instruments to control LED lamps with red, green, blue, and amber colors for MEG brain scans. A software was also developed to generate various colors and predefined white light combinations using RGBA color pallets. The feasibility of using LED lamps with MEG brain scanners has been validated for biomedical and psychological experiments.
APPLIED SCIENCES-BASEL
(2023)
Article
Physics, Applied
Ran-Ran Xie, Han Zhu, Ruofei Xing, Lingrui Chu, Zhuoqun Wang, Ruyi Xia, Wenxiao Zhao, Yuechen Jia, Yanxue Chen, Saulius Juodkazis, Feng Chen
Summary: This study investigates the modulation of crystallinity and morphology of vanadium dioxide thin film using femtosecond laser direct writing. The research explores the impact of femtosecond laser conditions on the evolution of nano/micro-structures and demonstrates the ability to draw a multi-color image on a VO2 thin film. This work provides a new method for producing complex integrated multi-functional devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Federico Melli, Lorenzo Rosa, Luca Vincetti
Summary: Simple analytical formulas are proposed for micro-bending and surface scattering loss in Hollow-Core Tube Lattice Fibers and validated numerically. These formulas can also be applied to other Hollow-Core fibers with similar core-cladding interfaces. Scaling laws for both loss mechanisms are provided and discussed.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Hsin-Hui Huang, Saulius Juodkazis, Eugene G. Gamaly, Vladimir T. Tikhonchuk, Koji Hatanaka
Summary: This study analyzes the processes produced by the interaction of two subsequent ultra-short laser pulses with a water flow, and finds that this interaction generates strong THz pulses and enhanced X-ray emission. It is demonstrated that these emissions are produced by the interaction of a main laser pulse with liquid water ejected from the surface by a pre-pulse, resulting in the acceleration of energetic electron beams. This scheme enables efficient energy conversion in THz pulses.
Article
Chemistry, Multidisciplinary
Soon Hock Ng, Vijayakumar Anand, Molong Han, Daniel Smith, Jovan Maksimovic, Tomas Katkus, Annaleise Klein, Keith Bambery, Mark J. Tobin, Jitraporn Vongsvivut, Saulius Juodkazis
Summary: The FTIRm system of the Australian Synchrotron has a unique optical configuration and uses a Schwarzschild objective to focus the beam onto the sample for image scanning. In this study, the Lucy-Richardson-Rosen algorithm (LRRA) was applied for the first time in the online FTIRm system to improve image reconstruction. This new technique called coded aperture scanning holography was demonstrated with various samples for image recovery and 3D imaging applications.
APPLIED SCIENCES-BASEL
(2023)
Article
Nanoscience & Nanotechnology
Lingrui Chu, Haoran Mu, Han Zhu, Bo Wu, Weijie Liu, Saulius Juodkazis, Feng Chen
Summary: The research introduces an ultrathin titanium film between gold film and fused silica substrate to generate surface plasmon polariton waves. The femtosecond laser-SPPs patterning technique produces high quality gold nanoribbons with a width of about 270 nm and a spatial period of about 700 nm, allowing for rapid and cost-effective production of large-scale plasmonic nanostructures.
MATERIALS TODAY NANO
(2023)
