In the displacement measurement of the wafer stage in lithography machines, signal quality is affected by the relative angular position between the encoder head and the grating. In this study, a two-degree-of-freedom fiber-coupled heterodyne grating interferometer with large operating range of rotation is presented. Fibers without fiber couplers are utilized to receive the interference beams for high-contrast signals under the circumstances of large angular displacement and ZEMAX ray tracing software simulation and experimental validation have been carried out. Meanwhile, a reference beam generated inside the encoder head is adopted to suppress the thermal drift of the interferometer. Experimental results prove that the proposed grating interferometer could realize sub-nanometer displacement measurement stability in both in-plane and out-of-plane directions, which is 0.246 nm and 0.465 nm of 3σ value respectively within 30 s.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6679590 | PMC |
| http://dx.doi.org/10.3390/s19143219 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Grating-based x-ray dark-field mammography: Assessing complementary imaging information in simple cystic lesions and typical fibroadenoma.
Med Phys
January 2025
Breast Imaging Department, Red Cross Hospital Munich, Munich, Germany.
Background: A significant proportion of false positive recalls of mammography-screened women is due to benign breast cysts and simple fibroadenomas. These lesions appear mammographically as smooth-shaped dense masses and require the recalling of women for a breast ultrasound to obtain complementary imaging information. They can be identified safely by ultrasound with no need for further assessment or treatment.
View Article and Find Full Text PDFArticle Synopsis
- The proposed hybrid photonic platform combines chalcogenide glass (GeSbSe) with lithium niobate on insulator (LNOI) to enhance performance and compactness for integrated photonic systems.
- Key components such as grating couplers, micro-ring resonators, multimode interference couplers, and Mach-Zehnder interferometers are designed and fabricated, achieving high quality factors and low propagation losses.
- This platform's unique optical properties allow for scalable, low-loss integrated photonic circuits, making it suitable for applications in high-speed optical communications and signal processing.
On the origin of MTF reduction in grating-based x-ray differential phase contrast CT imaging.
Med Phys
December 2024
Research Center for Advanced Detection Materials and Medical Imaging Devices, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China.
Background: The complementary absorption contrast CT (ACT) and differential phase contrast CT (DPCT) can be generated simultaneously from an x-ray computed tomography (CT) imaging system incorporated with grating interferometer. However, it has been reported that ACT images exhibit better spatial resolution than DPCT images. By far, the primary cause of such discrepancy remains unclear.
View Article and Find Full Text PDFAn enhanced distributed acoustic sensing (DAS) is proposed based on an extended Mach-Zehnder interferometer utilizing quantum weak measurement. The acoustic signals are encoded as the relative phase of the polarized light in several channels by fibers between optical fiber Bragg gratings (FBGs). With appropriate preselection and postselection, the acoustic signal can be extracted by performing the Fourier transform on the contrast ratio of the detected light intensity.
View Article and Find Full Text PDFFiber-Optic Sensor Spectrum Noise Reduction Based on a Generative Adversarial Network.
Sensors (Basel)
November 2024
School of Information Engineering, Huzhou University, Huzhou 313000, China.
Article Synopsis
- This study introduces a deep-learning denoising method that transforms fiber-optic sensor spectra into 2D images and uses a Cycle-GAN model to improve signal quality.
- It demonstrates significant improvements in signal-to-noise ratio (SNR), root mean square error (RMSE), and high correlation with original signals compared to traditional denoising methods like wavelet transform and empirical mode decomposition.
- The proposed algorithm successfully reduces noise across different fiber-optic sensors and shows excellent linearity in temperature response, making fiber-optic sensing more effective for various research and industrial applications.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!