98%
921
2 minutes
20
The process of Zernike mode detection with a Shack-Hartmann wavefront sensor is computationally extensive. A holographic modal wavefront sensor has therefore evolved to process the data optically by use of the concept of equal and opposite phase bias. Recently, a multiplexed computer-generated hologram (CGH) technique was developed in which the output is in the form of bright dots that specify the presence and strength of a specific Zernike mode. We propose a wavefront sensor using the concept of phase biasing in the latter technique such that the output is a pair of bright dots for each mode to be sensed. A normalized difference signal between the intensities of the two dots is proportional to the amplitude of the sensed Zernike mode. In our method the number of holograms to be multiplexed is decreased, thereby reducing the modal cross talk significantly. We validated the proposed method through simulation studies for several cases. The simulation results demonstrate simultaneous wavefront detection of lower-order Zernike modes with a resolution better than lambda/50 for the wide measurement range of +/-3.5lambda with much reduced cross talk at high speed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/AO.48.006458 | DOI Listing |
Nanophotonics
August 2025
Department of Electronic Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
Under-display camera (UDC) systems enable full-screen displays in smartphones by embedding the camera beneath the display panel, eliminating the need for notches or punch holes. However, the periodic pixel structures of display panels introduce significant optical diffraction effects, leading to imaging artifacts and degraded visual quality. Conventional approaches to mitigate these distortions, such as deep learning-based image reconstruction, are often computationally expensive and unsuitable for real-time applications in consumer electronics.
View Article and Find Full Text PDFSensors (Basel)
August 2025
School of Information and Communication Engineering, Communication University of China, Beijing 100024, China.
Integrated Sensing And Communication (ISAC) has been applied to the Internet of Things (IoT) network as a promising 6G technology due to its ability to enhance spectrum utilization and reduce resource consumption, making it ideal for high-precision sensing applications. However, while the introduction of millimeter Wave (mmWave) and massive Multiple-Input Multiple-Output (MIMO) technologies can enhance the performance of ISAC systems, they extend the near-field region, rendering traditional channel parameter estimation algorithms ineffective due to the spherical wavefront channel model. Aiming to address the challenge, we propose a tensor-based channel parameter estimation and localization algorithm for the near-field mmWave massive MIMO-Orthogonal Frequency Division Multiplexing (OFDM) ISAC systems.
View Article and Find Full Text PDFSensors (Basel)
August 2025
Key Laboratory of Vibration Signal Capture and Intelligent Processing, School of Electronic Engineering, Yili Normal University, 448 Jiefang Road, Yining 835000, China.
In geophysical exploration, laser remote sensing detection of seismic waves based on wavefront sensors can be used for geological detection and geophysical exploration. However, due to the high sensitivity of the wavefront sensor, it is easy to be affected by the environmental light and vibration, resulting in random noise, which is difficult to predict, thus significantly reducing the quality of the vibration signal and the detection accuracy. In this paper, a large amount of data is collected through a single-point vibration detection experiment, and the relationship between amplitude and spot centroid offset is analyzed and calculated.
View Article and Find Full Text PDFBiomed Opt Express
August 2025
College of Optometry, University of Houston, Houston, TX 77204, USA.
To quantify high-spatial-frequency wavefront errors caused by microaberration, we developed a high-resolution (20 µm) Shack-Hartmann wavefront sensor (SHWFS). This system was designed using a small lenslet array (100 µm) and a large CMOS sensor (24.6 × 32.
View Article and Find Full Text PDFUnderstanding pump-induced lensing in laser amplifiers is important for power scaling of solid-state lasers with maintenance of high beam quality, however, there is still incomplete knowledge of the relative role of different lensing processes, particularly between thermally-induced lensing and excited-state population-induced lensing. In this study, we directly measure the transient dioptric lensing in the diode-pumped neodymium-doped yttrium vanadate (Nd:YVO) gain medium using a time-gated wavefront sensor. Pulsed pump-probe measurements of the transient growth and decay of pump-induced lensing clearly distinguish thermal and population lensing mechanisms by their different time signatures.
View Article and Find Full Text PDF