Article
Optics
Ajith Ravindran, D. Nirmal, K. P. Pinkymol, P. Prajoon, J. Ajayan, Subhash Chander
Summary: This article presents a method based on reflectance spectroscopy to evaluate the severity of skin lesions in localized scleroderma, and proposes a TiO2 grating with optimized parameters for efficient detection.
Review
Engineering, Electrical & Electronic
Ajith Ravindran, D. Nirmal, P. Prajoon, D. Gracia Nirmala Rani
Summary: This paper investigates the innovations of spectrometers for handheld MEMS spectrometers, emphasizing the importance of grating parameters and recent developments. Key factors such as grating efficiency, groove density, free spectral range, and resolving power significantly impact grating performance. The use of materials like silicon, silicon dioxide, glass, PMMA, chromium, and silicon nitride play a crucial role in the efficiency of the grating.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Ajith Ravindran, D. Nirmal, Binola K. I. Jebalin, K. P. Pinkymol, P. Prajoon, J. Ajayan
Summary: This paper investigates a one-dimensional InGaAs grating structure for UV-VIS spectrometer used in mRNA vaccine development. By incorporating new materials and optimizing parameters, the performance of the grating and spectrometer is improved, providing a reliable tool for mRNA vaccine development.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Xufeng Jing, Xiaoyan Tang, Ying Tian, Zhe Kong, Chenxia Li, Changyu Shen, Zhi Hong
Summary: This paper introduces an innovative principle of adding coded gratings, which can enhance diffraction efficiency and flexibly adjust the scattering angle. This method can also be applied to optical or microwave bands, providing a new approach for electromagnetic wave modulation and beam scanning.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Yan Li, Minghao Zuo, Jifang Tao
Summary: In this study, an optical interferometric acoustic sensor was developed to overcome the performance limitations caused by damping in the air gap of a small capacitive MEMS microphone. The sensor chip incorporates a diffraction grating integrated backplate and a pressure-sensitive diaphragm, forming a grating interferometer. The sensor parameters were optimized using scalar diffraction theory and finite-element method. The sensor was fabricated on a CMOS-compatible SOI wafer and its performance was evaluated using an acoustic testing system. It demonstrated a good linear relationship with applied sound pressure and a frequency response consistent with a commercial reference microphone for audible range, with a SNR of about 43 dB at 1 kHz. The proposed design shows great potential for high-performance acoustic sensors.
IEEE SENSORS JOURNAL
(2023)
Article
Optics
Yourong Liu, Tong Shen, Biao Kang, Shaoxing Li, Zengrong Zheng, Huaqing Lv, Jihong Zheng
Summary: This paper investigates the effects of using a composite photopolymer system and a photoinitiator on the optical properties of a volume phase holographic grating. The study shows that the performance of the hologram can be improved under specific conditions, and demonstrates the high-density data recording capability of the photopolymer.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Yuchen Ge, Jiongshen Pan, Guangzheng Luo, L. i-Peng Sun, Bai-Ou Guan
Summary: This paper presents a detailed investigation into the sensing characteristics of a structural microfiber long-period grating (mLPG) sensor. The mLPG is obtained by spirally winding a thinner microfiber to another thicker microfiber, resulting in periodic refractive index modulation and strong resonant dip. Sensitivity characteristics of the mLPG to surrounding strain, force, temperature, and refractive index are studied, demonstrating high refractive index sensitivity and wide wavelength tunable range.
Article
Optics
Yuchen Ge, Jiongshen Pan, Guangzheng Luo, Li-peng Sun, Bai-ou Guan
Summary: We conducted a detailed investigation on the sensing characteristics of a structural microfiber long-period grating (mLPG) sensor. By spirally winding a thinner microfiber to another thicker microfiber, we achieved periodic refractive index modulation and resonant coupling of the optical signal. The four-port mLPG exhibited strong resonant dip and showed sensitivities to surrounding strain, force, temperature, and refractive index. With its high refractive index sensitivity and wide wavelength tunable range, this mLPG sensor holds great potential in applications such as tunable filters and biochemical sensors.
Article
Engineering, Electrical & Electronic
Jingquan Xu, Kexin Chen, Yingying Qu, Chen Liu, Songnian Fu, Deming Liu
Summary: This article presents a novel double gratings configuration based on LCOS optical filter, which achieves higher spectral resolution by enlarging and accumulating dispersion. With this configuration, a spectral resolution of 1.63 GHz is achieved, almost tenfold enhancement compared to traditional single grating configuration.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Cleaven Chia, Bartholomeus Machielse, Amirhassan Shams-Ansari, Marko Loncar
Summary: Diamond has good optical properties and has been successfully used for quantum photonic devices operating at visible wavelengths. However, fabricating larger devices for telecommunication wavelengths has been challenging. This study evaluated different mask materials and found that a thick hydrogen silesquioxane layer on a thin alumina adhesion layer produced the best etch profile and optical performance.
Article
Engineering, Electrical & Electronic
Daniele Melati, Mohsen Kamandar Dezfouli, Yuri Grinberg, Jens H. Schmid, Ross Cheriton, Siegfried Janz, Pavel Cheben, Dan-Xia Xu
Summary: Compact and efficient optical antennas are designed using grating-based micro-antennas with perfectly vertical emission. Through optimization and machine learning, high performance designs are discovered, achieving high diffraction and coupling efficiency with a one-step apodized grating.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Optics
Angshuman Deka, Dilyana S. Mihaylova, Svetlen H. Tonchev, Semyon L. Zheleznyak
Summary: A new method for fabricating dual-blazed gratings is introduced, which involves aligning and bonding two gratings to obtain a monolithic replica with maintained optical control. This technique allows for tailoring grating efficiencies over a broad wavelength range. Furthermore, the effect of the seam orientation between two sections on scatter properties is investigated.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Computer Science, Information Systems
F. Javier Garcia-Diaz, Omar Palillero-Sandoval, J. Jesus Escobedo-Alatorre, Miguel A. Basurto-Pensado, Pedro A. Marquez-Aguilar, Alvaro Zamudio-Lara, Jonny Paul Zavala-De Paz, Jose Antonio Marban-Salgado
Summary: This paper introduces a hyperspectral imaging system based on a diffraction grating, which can be used for analysis and characterization of objects, and obtain more information at a lower cost in spectral and hyperspectral imaging.
Article
Optics
Xiayu Feng, Lu Lu, Oleg Yaroshchuk, Philip Bos
Summary: This study provides a detailed investigation of transmissive polarization volume holograms, clarifying their geometry, physics, and optical responses through FDTD simulation and experimental validation. The configuration called Slanted T-PVH is found to have the advantageous property of maintaining circular output polarization states, which was validated with experiments.
Article
Engineering, Electrical & Electronic
Q. K. Xia, D. N. Wang
Summary: Optical fiber diffraction gratings with periodic structure fabricated by femtosecond laser are proposed and demonstrated. The adoption of multiple layer gratings greatly enhances the diffraction patterns and enables the construction of an optical fiber in-line Mach-Zehnder interferometer. These fiber diffraction gratings are characterized by high robustness, good operation stability, and great potential for various photonics applications.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
