scholarly journals Generation and imaging of a tunable ultrafast intensity-rotating optical field with a cycle down to femtosecond region

2020 ◽  
Vol 8 ◽  
Author(s):  
Xuanke Zeng ◽  
Shuiqin Zheng ◽  
Yi Cai ◽  
Hongyu Wang ◽  
Xiaowei Lu ◽  
...  
Keyword(s):  
Repetition Rate ◽  
Rotational Symmetry ◽  
Michelson Interferometer ◽  
Optical Field ◽  
Frame Rate ◽  
Single Shot ◽  
Rotating Speed ◽  
Chirped Pulses ◽  
Laser Systems ◽  
The Difference

A tunable ultrafast intensity-rotating optical field is generated by overlapping a pair of 20 Hz, 800 nm chirped pulses with a Michelson interferometer (MI). Its rotating rate can be up to 10 trillion radians per second ( $\text{Trad}/\text{s}$ ), which can be flexibly tuned with a mirror in the MI. Besides, its fold rotational symmetry structure is also changeable by controlling the difference from the topological charges of the pulse pair. Experimentally, we have successfully developed a two-petal lattice with a tunable rotating speed from $3.9~\text{Trad}/\text{s}$ up to $11.9~\text{Trad}/\text{s}$ , which is confirmed by our single-shot ultrafast frame imager based on noncollinear optical-parametric amplification with its highest frame rate of 15 trillion frames per second (Tfps). This work is carried out at a low repetition rate. Therefore, it can be applied at relativistic, even ultrarelativistic, intensities, which usually operate in low repetition rate ultrashort and ultraintense laser systems. We believe that it may have application in laser-plasma-based accelerators, strong terahertz radiations and celestial phenomena.

Generalized Heterodyne Configurations for Photo-induced Force Microscopy

2019 ◽  
Author(s):  
Le Wang ◽  
Devon Jakob ◽  
Haomin Wang ◽  
Alexis Apostolos ◽  
Marcos M. Pires ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Repetition Rate ◽  
Modulation Frequency ◽  
High Harmonic ◽  
Chemical Imaging ◽  
Heterodyne Detection ◽  
Force Microscopy ◽  
Wide Range ◽  
The Difference ◽  
Afm Cantilever

<div>Infrared chemical microscopy through mechanical probing of light-matter interactions by atomic force microscopy (AFM) bypasses the diffraction limit. One increasingly popular technique is photo-induced force microscopy (PiFM), which utilizes the mechanical heterodyne signal detection between cantilever mechanical resonant oscillations and the photo induced force from light-matter interaction. So far, photo induced force microscopy has been operated in only one heterodyne configuration. In this article, we generalize heterodyne configurations of photoinduced force microscopy by introducing two new schemes: harmonic heterodyne detection and sequential heterodyne detection. In harmonic heterodyne detection, the laser repetition rate matches integer fractions of the difference between the two mechanical resonant modes of the AFM cantilever. The high harmonic of the beating from the photothermal expansion mixes with the AFM cantilever oscillation to provide PiFM signal. In sequential heterodyne detection, the combination of the repetition rate of laser pulses and polarization modulation frequency matches the difference between two AFM mechanical modes, leading to detectable PiFM signals. These two generalized heterodyne configurations for photo induced force microscopy deliver new avenues for chemical imaging and broadband spectroscopy at ~10 nm spatial resolution. They are suitable for a wide range of heterogeneous materials across various disciplines: from structured polymer film, polaritonic boron nitride materials, to isolated bacterial peptidoglycan cell walls. The generalized heterodyne configurations introduce flexibility for the implementation of PiFM and related tapping mode AFM-IR, and provide possibilities for additional modulation channel in PiFM for targeted signal extraction with nanoscale spatial resolution.</div>

scholarly journals Development of a single-shot third-order cross-correlator for picosecond laser systems

2021 ◽  
Vol 483 ◽  
pp. 126672
Author(s):  
A.C. Aiken ◽  
P. Oliveira ◽  
L.E. Bradley ◽  
E. Dilworth ◽  
M. Galletti ◽  
...  
Keyword(s):  
Picosecond Laser ◽  
Single Shot ◽  
Third Order ◽  
Laser Systems

scholarly journals Performance Evaluation of Ground AR Anchor with WebXR Device API

2021 ◽  
Vol 11 (17) ◽  
pp. 7877
Author(s):  
Daehyeon Lee ◽  
Woosung Shim ◽  
Munyong Lee ◽  
Seunghyun Lee ◽  
Kye-Dong Jung ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Mixed Reality ◽  
Ground Truth ◽  
Application Programming Interface ◽  
Absolute Error ◽  
Frame Rate ◽  
Difference Image ◽  
Match Rate ◽  
The Difference ◽  
The Web

Recently, the development of 3D graphics technology has led to various technologies being combined with reality, where a new reality is defined or studied; they are typically named by combining the name of the technology with “reality”. Representative “reality” includes Augmented Reality, Virtual Reality, Mixed Reality, and eXtended Reality (XR). In particular, research on XR in the web environment is actively being conducted. The Web eXtended Reality Device Application Programming Interface (WebXR Device API), released in 2018, allows instant deployment of XR services to any XR platform requiring only an active web browser. However, the currently released tentative version has poor stability. Therefore, in this study, the performance evaluation of WebXR Device API is performed using three experiments. A camera trajectory experiment is analyzed using ground truth, we checked the standard deviation between the ground truth and WebXR for the X, Y, and Z axes. The difference image experiment is conducted for the front, left, and right directions, which resulted in a visible difference image for each image of ground truth and WebXR, small mean absolute error, and high match rate. In the experiment for measuring the 3D rendering speed, a frame rate similar to that of real-time is obtained.

Stereoscopic Transparency and Segregation in Depth

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 90-90
Author(s):  
M J M Lankheet ◽  
M Palmen
Keyword(s):  
Temporal Integration ◽  
Frame Rate ◽  
Single Plane ◽  
Television Monitor ◽  
Depth Discontinuities ◽  
Sinusoidal Gratings ◽  
Random Dot Stereograms ◽  
Motion Contrast ◽  
The Difference ◽  
Method Of Constant Stimuli

We previously described the spatiotemporal requirements for binocular correlation in stereopsis using sinusoidal gratings-in-depth (Lankheet and Lennie, 1996 Vision Research36 527 – 538). The use of smooth sinusoidal surfaces emphasised the effects of spatial and temporal integration. Binocular correlation, however, depends not only on integration, but also on segregation at depth discontinuities. In the present experiments we therefore investigated segregation-in-depth, using random dot stereograms that depicted two transparent frontoparallel planes positioned symmetrically on either side of a binocular fixation point. Sensitivity for segregating the two planes was established by adding Gaussian distributed disparity noise to the disparities specifying the planes, and finding the noise amplitude that rendered transparency just detectable. The stimuli consisted of dynamic random-dot displays (dot lifetime 4 frames, at a frame rate of 67 Hz), generated in real time by a Macintosh computer, displayed on a television monitor, and viewed through a stereoscope. We used a method of constant stimuli and a 2AFC procedure. Two transparent planes were presented in one interval, and a single plane, with Gaussian distributed disparity values spanning the same range, was presented in the other. Segregation of stationary patterns was optimal for disparity differences of about ±9 min arc. Differences smaller than ±3 min arc and larger than about ±18 min arc could not be resolved. Motion contrast between the two patterns greatly facilitated segregation in depth. The facilitating effect increased with the difference in motion directions. The optimal speed varied with the difference in disparity.

scholarly journals On-Chip Multiple Particle Velocity and Size Measurement Using Single-Shot Two-Wavelength Differential Image Analysis

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1011
Author(s):  
Shuya Sawa ◽  
Mitsuru Sentoku ◽  
Kenji Yasuda
Keyword(s):  
Irradiation Time ◽  
Single Shot ◽  
Cross Sectional ◽  
Simple Method ◽  
Quick Measurement ◽  
The Difference ◽  
On Chip ◽  
Calculated Velocity ◽  
Multiple Particle ◽  
Flow Velocities

Precise and quick measurement of samples’ flow velocities is essential for cell sorting timing control and reconstruction of acquired image-analyzed data. We developed a simple technique for the single-shot measurement of flow velocities of particles simultaneously in a microfluidic pathway. The speed was calculated from the difference in the particles’ elongation in an acquired image that appeared when two wavelengths of light with different irradiation times were applied. We ran microparticles through an imaging flow cytometer and irradiated two wavelengths of light with different irradiation times simultaneously to those particles. The mixture of the two wavelength transmitted lights was divided into two wavelengths, and the images of the same microparticles for each wavelength were acquired in a single shot. We estimated the velocity from the difference of its elongation divided by the difference of irradiation time by comparing these two images. The distribution of polystyrene beads’ velocity was parabolic and highest at the center of the flow channel, consistent with the expected velocity distribution of the laminar flow. Applying the calculated velocity, we also restored the accurate shapes and cross-sectional areas of particles in the images, indicating this simple method for improving of imaging flow cytometry and cell sorter for diagnostic screening of circulating tumor cells.

scholarly journals Improving Signal and Photobleaching Characteristics of Temporal Focusing Microscopy with the Increase in Pulse Repetition Rate

2019 ◽  
Vol 2 (3) ◽  
pp. 65
Author(s):  
Viktoras Lisicovas ◽  
Bala Murali Krishna Mariserla ◽  
Chakradhar Sahoo ◽  
Reuben T. Harding ◽  
Michael K. L. Man ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Repetition Rate ◽  
Signal Intensity ◽  
High Repetition Rate ◽  
High Peak Power ◽  
High Pulse Energy ◽  
Two Photon ◽  
High Repetition ◽  
Laser Systems ◽  
High Pulse

Wide-field temporal focused (WF-TeFo) two-photon microscopy allows for the simultaneous imaging of a large planar area, with a potential order of magnitude enhancement in the speed of volumetric imaging. To date, low repetition rate laser sources with over half a millijoule per pulse have been required in order to provide the high peak power densities for effective two-photon excitation over the large area. However, this configuration suffers from reduced signal intensity due to the low repetition rate, saturation effects due to increased excitation fluences, as well as faster photobleaching of the fluorescence probe. In contrast, with the recent advent of high repetition rate, high pulse energy laser systems could potentially provide the advantages of high repetition rate systems that are seen in traditional two-photon microscopes, while minimizing the negatives of high fluences in WF-TeFo setups to date. Here, we use a 100 microjoule/high repetition rate (50–100 kHz) laser system to investigate the performance of a WF-TeFo two-photon microscope. While using micro-beads as a sample, we demonstrate a proportionate increase in signal intensity with repetition rate, at no added cost in photobleaching. By decreasing pulse intensity, via a corresponding increase in repetition rate to maintain fluorescence signal intensity, we find that the photobleaching rate is reduced by ~98.4%. We then image live C. elegans at a high repetition rate for 25 min. as a proof-of-principle. Lastly, we identify the steady state temperature increase as the limiting process in further increasing the repetition rate, and we estimate that repetition rate in the range between 0.5 and 5 MHz is ideal for live imaging with a simple theoretical model. With new generation low-cost fiber laser systems offering high pulse energy/high repetition rates in what is essentially a turn-key solution, we anticipate increased adoption of this microscopy technique by the neuroscience community.

scholarly journals Light-In-Flight Imaging by a Silicon Image Sensor: Toward the Theoretical Highest Frame Rate

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2247 ◽  
Author(s):  
Takeharu Etoh ◽  
Tomoo Okinaka ◽  
Yasuhide Takano ◽  
Kohsei Takehara ◽  
Hitoshi Nakano ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
High Speed ◽  
Streak Camera ◽  
Image Sensor ◽  
Pulse Neutron ◽  
Frame Rate ◽  
Neutron Tomography ◽  
Single Shot ◽  
Resolution Limit ◽  
Lifetime Measurements

Light in flight was captured by a single shot of a newly developed backside-illuminated multi-collection-gate image sensor at a frame interval of 10 ns without high-speed gating devices such as a streak camera or post data processes. This paper reports the achievement and further evolution of the image sensor toward the theoretical temporal resolution limit of 11.1 ps derived by the authors. The theoretical analysis revealed the conditions to minimize the temporal resolution. Simulations show that the image sensor designed following the specified conditions and fabricated by existing technology will achieve a frame interval of 50 ps. The sensor, 200 times faster than our latest sensor will innovate advanced analytical apparatuses using time-of-flight or lifetime measurements, such as imaging TOF-MS, FLIM, pulse neutron tomography, PET, LIDAR, and more, beyond these known applications.

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