A new near-field processing method by femtosecond laser ablation using photoresist enhancing masks is numerically and experimentally investigated. Periodical structures with 2 μm pitch, 1 μm width and 300 nm height, created in polymethyl methacrylate photoresist by e-beam lithography, were used to intensify the incident laser radiation. The near-field distribution and the intensification factor of the optical radiation were computed using the Finite-Difference-Time-Domain numerical simulations. The pattern of the photoresist mask was imprinted on the surface of a silicon wafer. Using a single infrared femtosecond laser pulse, uniform and continuum grooves with the width in the range of 250 nm were obtained on large silicon surface.
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http://dx.doi.org/10.1364/OE.22.003356 | DOI Listing |
Silicon carbide (SiC) ceramics have emerged as critical materials in the production of high-precision components. Ultrafast laser processing is deemed the optimal technique for micro-nano manufacturing of SiC. However, the permanent deposition layer induced by laser ablation can critically impact the precision of the component.
View Article and Find Full Text PDFMicromachines (Basel)
March 2023
Optical Sciences Centre, Australian Research Council (ARC) Industrial Transformation Training Centre in Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
Microlens arrays (MLAs) which are increasingly popular micro-optical elements in compact integrated optical systems were fabricated using a femtosecond direct laser write (fs-DLW) technique in the low-shrinkage SZ2080 photoresist. High-fidelity definition of 3D surfaces on IR transparent CaF substrates allowed to achieve ∼50% transmittance in the chemical fingerprinting spectral region 2-5 μm wavelengths since MLAs were only ∼10 μm high corresponding to the numerical aperture of 0.3 (the lens height is comparable with the IR wavelength).
View Article and Find Full Text PDFNanomaterials (Basel)
May 2023
College of Intelligent System Science and Engineering, Shenyang University, Shenyang 110044, China.
Micro-optics based on the artificial adjustment of physical dimensions, such as the phase, polarization, and wavelength of light, constitute the basis of contemporary information optoelectronic technology. As the main means of optical integration, it has become one of the important ways to break through the future bottleneck of microelectronic technology. Geometric phase optical components can precisely control the polarization, phase, amplitude and other properties of the light field at the sub-wavelength scale by periodically arranging nanometer-sized unit structures.
View Article and Find Full Text PDFNat Commun
October 2022
Department of Mechanical and Energy Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen, 518055, China.
Rigorously designed sub-micrometer structure arrays are widely used in metasurfaces for light modulation. One of the glaring restrictions is the unavailability of easily accessible fabrication methods to efficiently produce large-area and freely designed structure arrays with nanoscale resolution. We develop a patterned pulse laser lithography (PPLL) approach to create structure arrays with sub-wavelength feature resolution and periods from less than 1 μm to over 15 μm on large-area thin films with substrates under ambient conditions.
View Article and Find Full Text PDFMicromachines (Basel)
September 2022
Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou 510632, China.
At present, there is an increasing need to mimic the in vivo micro-environment in the culture of cells and tissues in micro-tissue engineering. Concave microwells are becoming increasingly popular since they can provide a micro-environment that is closer to the in vivo environment compared to traditional microwells, which can facilitate the culture of cells and tissues. Here, we will summarize the fabrication methods of concave microwells, as well as their applications in micro-tissue engineering.
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