We demonstrate a novel electronic readout for quadrant photodiode based optical beam deflection setups. In our readout, the signals used to calculate the deflections remain as currents, instead of undergoing an immediate conversion to voltages. Bipolar current mirrors are used to perform all mathematical operations at the transistor level, including the signal normalizing division. This method has numerous advantages, leading to significantly simpler designs that avoid large voltage swings and parasitic capacitances. The bandwidth of our readout is solely limited by the capacitance of the quadrant photodiode junctions, making the effective bandwidth a function of the intensity of photocurrents and thus the applied power of the beam deflection laser. Using commercially available components and laser intensities of 1-4 mW we achieved a 3 dB bandwidth of 20 MHz with deflection sensitivities of up to 0.5-1 V/nm and deflection noise levels below 4.5 fm/Hz. Atomic resolution imaging of muscovite mica using FM-AFM in water demonstrates the sensitivity of this novel readout.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/1.3575322 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Structural design and safety performance of a novel high-strength steel lightweight guardrail.
PLoS One
January 2025
Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai, China.
Highway guardrails are critical safety infrastructure along roadways, designed to redirect vehicles back into their lanes and facilitate a gradual deceleration to a complete stop. Traditional highway steel guardrails exhibit significant limitations, including inadequate energy absorption, susceptibility to corrosion, and an increased risk of vehicles leaving the roadway during severe collisions. Furthermore, the production and transportation of these guardrails contribute to substantial carbon emissions and environmental pollution.
View Article and Find Full Text PDFGesture-controlled reconfigurable metasurface system based on surface electromyography for real-time electromagnetic wave manipulation.
Nanophotonics
January 2025
Key Laboratory for Information Science of Electromagnetic Waves, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
Gesture recognition plays a significant role in human-machine interaction (HMI) system. This paper proposes a gesture-controlled reconfigurable metasurface system based on surface electromyography (sEMG) for real-time beam deflection and polarization conversion. By recognizing the sEMG signals of user gestures through a pre-trained convolutional neural network (CNN) model, the system dynamically modulates the metasurface, enabling precise control of the deflection direction and polarization state of electromagnetic waves.
View Article and Find Full Text PDFResponse of negative ion beamlet width and axis deflection to RF field in beam extraction region.
Sci Rep
January 2025
Max-Planck Institute for Plasma Physics, Garching, 85748, Germany.
Beam-divergence characteristics of single negative ion beamlet have been experimentally investigated with a superimposition of a controlled perturbation of a radio frequency wave (RF) field in a filament-arc discharge negative ion source. Oscillations of a negative-ion beamlet width and axis responding to the RF perturbation were observed, which may be a cause of the larger beam divergence angle of the RF negative ion source for ITER. It is pointed out that the oscillation of the beamlet width depends on the perveance and on an RF frequency such that the oscillation is suppressed at perveance-matched conditions and at low RF frequency.
View Article and Find Full Text PDF3D Femtosecond Laser Beam Deflection for High-Precision Fabrication and Modulation of Individual Voxelated PCM Meta-Atoms.
Adv Sci (Weinh)
January 2025
Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China.
Optical metasurfaces have found widespread applications in the field of optoelectronic devices. However, achieving dynamic and flexible control over metasurface functionalities, while also developing simplified fabrication methods for metasurfaces, continues to pose a significant challenge. Here, the study introduces a PCM-only metasurface that exclusively consists of voxel units crafted from different phases of phase-change materials.
View Article and Find Full Text PDFPhotoreconfigurable Metasurface for Independent Full-Space Control of Terahertz Waves.
Sensors (Basel)
December 2024
Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China.
We present a novel photoreconfigurable metasurface designed for independent and efficient control of electromagnetic waves with identical incident polarization and frequency across the entire spatial domain. The proposed metasurface features a three-layer architecture: a top layer incorporating a gold circular split ring resonator (CSRR) filled with perovskite material and dual -shaped perovskite resonators; a middle layer of polyimide dielectric; and a bottom layer comprising a perovskite substrate with an oppositely oriented circular split ring resonator filled with gold. By modulating the intensity of a laser beam, we achieve autonomous manipulation of incident circularly polarized terahertz waves in both transmission and reflection modes.
View Article and Find Full Text PDFWant 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!