We report highly efficient diffractive beam splitters intended for high-power laser applications. Submicron relief structures that work as an antireflective layer are formed on the surfaces of a splitter to improve its transmitted efficiency. Surface structuring is performed using deep-UV interference lithography and reactive ion etching. As immersed in an index-matching liquid, the resist layer coated on diffractive surfaces is exposed to the interference fringes that are set intersecting the grooves on the surfaces. Rigorously designed structures with a period of 140 nm and a depth of 55 nm are lithographed onto fused-silica splitters. Splitting efficiencies at 266 nm are increased by 8% to compare favorably with a theoretical value, while Fresnel reflections are considerably reduced.
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http://dx.doi.org/10.1364/AO.48.005105 | DOI Listing |
J Opt Soc Am A Opt Image Sci Vis
August 2024
A fused-silica three-port grating under TE-polarized normal incidence is designed and manufactured with improved diffraction efficiency (DE) and bandwidth. A physical explanation of the grating diffraction is provided using the simplified mode method (SMM), and parameters of the grating structure were optimized using rigorous coupled-wave analysis (RCWA). For a given set of optimized parameters, a transmitted three-port grating with an area of 170 ×170 was fabricated by scanning beam interference lithography (SBIL), and diffraction properties were investigated.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
August 2024
In the pinhole point diffraction interferometer (PPDI), proper alignment between the reflection spot of the tested component and the pinhole is critical to obtain accurate interferograms. At present, adjusting for tilt error requires manual manipulation, and defocus error cannot be corrected. These limitations impede the instrumentation process of PPDI.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
CNR-IOM-Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, 34149 Trieste, Italy.
Hybrid systems consisting of highly transparent channels of low-dimensional semiconductors between superconducting elements allow the formation of quantum electronic circuits. Therefore, they are among the novel material platforms that could pave the way for scalable quantum computation. To this aim, InAs two-dimensional electron gases are among the ideal semiconductor systems due to their vanishing Schottky barrier; however, their exploitation is limited by the unavailability of commercial lattice-matched substrates.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea.
In this paper, we demonstrate a blazed phase grating to achieve tunable beam steering and propose a novel algorithm to reduce the stripe noise in wrapped phase. To control the diffraction angle to steer light to the desired direction, an electrically tunable transmission-type beam deflector based on liquid crystals is introduced, and electric fields are applied to the patterned indium tin oxide electrodes to change its phase retardation. Two different 2π phase-wrapping methods are applied to obtain various diffraction angles within the minimum cell-gap, and the method of equal interval of phase achieves a worthwhile diffraction efficiency compared to the methods based on equal interval of diffraction angle.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Key Laboratory of All Optical Network and Advanced Telecommunication Network, Ministry of Education, Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044, China.
Diffractive optical elements (DOEs) are specialized optical components that manipulate light through diffraction for various applications, including holography, spectroscopy, augmented reality (AR) and virtual reality (VR), and light detection and ranging (LiDAR). The performance of DOEs is highly determined by fabricated materials and fabrication methods, in addition to the numerical simulation design. This paper presents a microfabrication technique optimized for DOEs, enabling precise control of critical parameters, such as refractive index (RI) and thickness.
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