scholarly journals Luminescence of water in Lake Baikal observed with the Baikal-GVD neutrino telescope

2019 ◽  
Vol 207 ◽  
pp. 09002
Author(s):  
A.D. Avrorin ◽  
A.V. Avrorin ◽  
V.M. Aynutdinov ◽  
R. Bannash ◽  
I.A. Belolaptikov ◽  
...  

We present data on the luminescence of the Baikal water medium collected with the Baikal-GVD neutrino telescope. This three-dimensional array of light sensors allows the observation of time and spatial variations of the ambient light field. In 2016, we observed a maximum of luminescence activity between July and October.

2021 ◽  
Vol 16 (11) ◽  
pp. C11011
Author(s):  
V.A. Allakhverdyan ◽  
A.D. Avrorin ◽  
A.V. Avrorin ◽  
V.M. Aynutdinov ◽  
R. Bannasch ◽  
...  

Abstract The Baikal-GVD is a neutrino telescope situated in the deepest freshwater lake in the world — Lake Baikal. The design of the Baikal-GVD trigger system allows also to study the ambient light of the lake. The analysis of the optical light activity of Baikal water, particularly, time and spatial variations of the luminescence activity for data collected in years 2018, 2019, and 2020 is presented. For the first time we observed highly luminescent layer moving upwards with maximal speed of 28 m/day in January 2021.


i-Perception ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 204166952095209
Author(s):  
James T. Todd

In 1966, James Gibson first presented his theory of the ambient optic array, and he proposed a new field of ecological optics that he hoped would advance our knowledge on this topic. This study will consider how his ideas have largely come to fruition over the past 50 years. It reviews the research on the visual perception of three-dimensional shape from shading, the effects of ambient light from surface interreflections on observers’ perceptions, the perception of the light field, and the perception of surface materials. Finally, it also considers Gibson’s impact on these developments.


Author(s):  
T. Orazgali

The deep underwater Neutrino Telescope Baikal NT1000 has been deployed in Lake Baikal since 2015. Detector is mainly designed to study astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The first stage NT1000 will be an array of 2300 optical modules with an instrumental volume of about 0.4 cubic kilometers, which is planned to be completed by 2020–2021. The properties of Baikal water and a combination of other related circumstances make it possible to create a unique installation in the world practice in sensitivity and angular resolution, opening up new horizons in astronomy and astrophysics. In this article basic information about the NT1000 and the being developed method to measure the optical characteristics at the detector’s water medium using a high-power laser light source are provided.


Author(s):  
Ying Yuan ◽  
Xiaorui Wang ◽  
Yang Yang ◽  
Hang Yuan ◽  
Chao Zhang ◽  
...  

Abstract The full-chain system performance characterization is very important for the optimization design of an integral imaging three-dimensional (3D) display system. In this paper, the acquisition and display processes of 3D scene will be treated as a complete light field information transmission process. The full-chain performance characterization model of an integral imaging 3D display system is established, which uses the 3D voxel, the image depth, and the field of view of the reconstructed images as the 3D display quality evaluation indicators. Unlike most of the previous research results using the ideal integral imaging model, the proposed full-chain performance characterization model considering the diffraction effect and optical aberration of the microlens array, the sampling effect of the detector, 3D image data scaling, and the human visual system, can accurately describe the actual 3D light field transmission and convergence characteristics. The relationships between key parameters of an integral imaging 3D display system and the 3D display quality evaluation indicators are analyzed and discussed by the simulation experiment. The results will be helpful for the optimization design of a high-quality integral imaging 3D display system.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
A. Patscheider ◽  
B. Zhu ◽  
L. Chomaz ◽  
D. Petter ◽  
S. Baier ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1920
Author(s):  
Chang Wang ◽  
Zeqing Yu ◽  
Qiangbo Zhang ◽  
Yan Sun ◽  
Chenning Tao ◽  
...  

Near-eye display (NED) systems for virtual reality (VR) and augmented reality (AR) have been rapidly developing; however, the widespread use of VR/AR devices is hindered by the bulky refractive and diffractive elements in the complicated optical system as well as the visual discomfort caused by excessive binocular parallax and accommodation-convergence conflict. To address these problems, an NED system combining a 5 mm diameter metalens eyepiece and a three-dimensional (3D), computer-generated holography (CGH) based on Fresnel diffraction is proposed in this paper. Metalenses have been extensively studied for their extraordinary capabilities at wavefront shaping at a subwavelength scale, their ultrathin compactness, and their significant advantages over conventional lenses. Thus, the introduction of the metalens eyepiece is likely to reduce the issue of bulkiness in NED systems. Furthermore, CGH has typically been regarded as the optimum solution for 3D displays to overcome limitations of binocular systems, since it can restore the whole light field of the target 3D scene. Experiments are carried out for this design, where a 5 mm diameter metalens eyepiece composed of silicon nitride anisotropic nanofins is fabricated with diffraction efficiency and field of view for a 532 nm incidence of 15.7% and 31°, respectively. Furthermore, a novel partitioned Fresnel diffraction and resample method is applied to simulate the wave propagations needed to produce the hologram, with the metalens capable of transforming the reconstructed 3D image into a virtual image for the NED. Our work combining metalens and CGH may pave the way for portable optical display devices in the future.


i-Perception ◽  
2017 ◽  
Vol 8 (1) ◽  
pp. 204166951668608 ◽  
Author(s):  
Ling Xia ◽  
Sylvia C. Pont ◽  
Ingrid Heynderick

Humans are able to estimate light field properties in a scene in that they have expectations of the objects’ appearance inside it. Previously, we probed such expectations in a real scene by asking whether a “probe object” fitted a real scene with regard to its lighting. But how well are observers able to interactively adjust the light properties on a “probe object” to its surrounding real scene? Image ambiguities can result in perceptual interactions between light properties. Such interactions formed a major problem for the “readability” of the illumination direction and diffuseness on a matte smooth spherical probe. We found that light direction and diffuseness judgments using a rough sphere as probe were slightly more accurate than when using a smooth sphere, due to the three-dimensional (3D) texture. We here extended the previous work by testing independent and simultaneous (i.e., the light field properties separated one by one or blended together) adjustments of light intensity, direction, and diffuseness using a rough probe. Independently inferred light intensities were close to the veridical values, and the simultaneously inferred light intensity interacted somewhat with the light direction and diffuseness. The independently inferred light directions showed no statistical difference with the simultaneously inferred directions. The light diffuseness inferences correlated with but contracted around medium veridical values. In summary, observers were able to adjust the basic light properties through both independent and simultaneous adjustments. The light intensity, direction, and diffuseness are well “readable” from our rough probe. Our method allows “tuning the light” (adjustment of its spatial distribution) in interfaces for lighting design or perception research.


2021 ◽  
pp. 127032
Author(s):  
Li Liu ◽  
Xinzhu Sang ◽  
Xunbo Yu ◽  
Xin Gao ◽  
Boyang Liu ◽  
...  

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