We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective ang...We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective angle on the signal-to-noise ratio(SNR) is analyzed by measuring the second-order correlation of the light field based on classical statistical optics. It is shown that the SNR decreases with an increment of the surface roughness and the detector's transverse size or a decrease of the reflective angle. Additionally, the comparative studies between the rough object and the smooth one under the same conditions are also discussed.展开更多
The far-field imaging properties of a high index microsphere lens spatially separated from the object are experimentally studied. Our experimental results show that, for a Blu-ray disk whose spacing is 300 nm, the hig...The far-field imaging properties of a high index microsphere lens spatially separated from the object are experimentally studied. Our experimental results show that, for a Blu-ray disk whose spacing is 300 nm, the high index microsphere lens also can discern the patterns of the object sample when the distance between the lens and the object is up to 5.4 μm. When the distance is increased from 0 to 5.4 μm, for the microsphere lens with a diameter of 24 μm, the lateral magnification increases from 3.5× to 5.5×, while the field of view decreases from 5.1 to 3.0 μm. By varying the distance between the lens and the object, the optical image can be optimized. We also indicate that the far-field imaging capability of a high index microsphere lens is dependent on the electromagnetic field intensityprofile of the photonic nanojet under different positions of the microsphere lens.展开更多
All endoscopic imaging system using a plenoptic technique to reconstruct 3-D information is demonstrated and analyzed in this Letter. The proposed setup integrates a clinical surgical endoscope with a plenoptic camera...All endoscopic imaging system using a plenoptic technique to reconstruct 3-D information is demonstrated and analyzed in this Letter. The proposed setup integrates a clinical surgical endoscope with a plenoptic camera to achieve a depth accuracy error of about 1 mm and a precision error of about 2 mm, within a 25 mm×25 mm field of view, operating at 11 frames per second.展开更多
With pretty high surface tension, the room temperature liquid metal may inherit with unexpected be- haviors that conventional fluids could not own. Here, we disclosed the coalescence and ejection phenomena of liquid m...With pretty high surface tension, the room temperature liquid metal may inherit with unexpected be- haviors that conventional fluids could not own. Here, we disclosed the coalescence and ejection phenomena of liquid metal droplets via high-speed camera. It was experimen- tally found that, when gently contacting (rather than col- liding) two metal droplets with identical size together in NaOH solution, oscillating coalescence would happen which runs just like a spring after the interface ruptures and forms capillary waves. For two metal droplets with evidently different diameters, the coalescence induces rather unusual ejection phenomena. The large droplet would swallow part of the small one and then eject another much smaller droplet. Such phenomenon provides a direct evidence for the existence of electrical double layer on metal droplets. The dynamics fluid impacting behaviors were quantified through processing images from the recorded movies, and the basic differences between the liquid metal droplets and that of water droplets were clar- ified. Theoretical mechanisms related to the events were preliminarily interpreted. The present finding refreshes the basic understanding of the liquid metal droplets, which also suggests potential values of applying such fundamental effects to characterize viscosity, surface tension, electrical double layer of the metal fluids and droplet formations.展开更多
基金National Natural Science Foundation of China(NSFC)(61372102,61571183)Natural Science Foundation of Hunan Province(2017JJ1014)
文摘We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective angle on the signal-to-noise ratio(SNR) is analyzed by measuring the second-order correlation of the light field based on classical statistical optics. It is shown that the SNR decreases with an increment of the surface roughness and the detector's transverse size or a decrease of the reflective angle. Additionally, the comparative studies between the rough object and the smooth one under the same conditions are also discussed.
基金financial support for this research from the Doctoral Fund of Ministry of Education of China (No. 20133207110007)the National Natural Science Foundation of China (No. 61475073)
文摘The far-field imaging properties of a high index microsphere lens spatially separated from the object are experimentally studied. Our experimental results show that, for a Blu-ray disk whose spacing is 300 nm, the high index microsphere lens also can discern the patterns of the object sample when the distance between the lens and the object is up to 5.4 μm. When the distance is increased from 0 to 5.4 μm, for the microsphere lens with a diameter of 24 μm, the lateral magnification increases from 3.5× to 5.5×, while the field of view decreases from 5.1 to 3.0 μm. By varying the distance between the lens and the object, the optical image can be optimized. We also indicate that the far-field imaging capability of a high index microsphere lens is dependent on the electromagnetic field intensityprofile of the photonic nanojet under different positions of the microsphere lens.
基金supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Grant no.1R01EB020610
文摘All endoscopic imaging system using a plenoptic technique to reconstruct 3-D information is demonstrated and analyzed in this Letter. The proposed setup integrates a clinical surgical endoscope with a plenoptic camera to achieve a depth accuracy error of about 1 mm and a precision error of about 2 mm, within a 25 mm×25 mm field of view, operating at 11 frames per second.
基金This work was partially supported by the Re- search Funding of the Chinese Academy of Sciences (KGZD-EW-T04-4) and the National Natural Science Foundation of China (81071225).
文摘With pretty high surface tension, the room temperature liquid metal may inherit with unexpected be- haviors that conventional fluids could not own. Here, we disclosed the coalescence and ejection phenomena of liquid metal droplets via high-speed camera. It was experimen- tally found that, when gently contacting (rather than col- liding) two metal droplets with identical size together in NaOH solution, oscillating coalescence would happen which runs just like a spring after the interface ruptures and forms capillary waves. For two metal droplets with evidently different diameters, the coalescence induces rather unusual ejection phenomena. The large droplet would swallow part of the small one and then eject another much smaller droplet. Such phenomenon provides a direct evidence for the existence of electrical double layer on metal droplets. The dynamics fluid impacting behaviors were quantified through processing images from the recorded movies, and the basic differences between the liquid metal droplets and that of water droplets were clar- ified. Theoretical mechanisms related to the events were preliminarily interpreted. The present finding refreshes the basic understanding of the liquid metal droplets, which also suggests potential values of applying such fundamental effects to characterize viscosity, surface tension, electrical double layer of the metal fluids and droplet formations.