Spectral imaging and spectral LIDAR systems: moving toward compact nanophotonics-based sensing

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nanxi Li ◽  
Chong Pei Ho ◽  
I-Ting Wang ◽  
Prakash Pitchappa ◽  
Yuan Hsing Fu ◽  
...  

Abstract With the emerging trend of big data and internet-of-things, sensors with compact size, low cost and robust performance are highly desirable. Spectral imaging and spectral LIDAR systems enable measurement of spectral and 3D information of the ambient environment. These systems have been widely applied in different areas including environmental monitoring, autonomous driving, biomedical imaging, biometric identification, archaeology and art conservation. In this review, modern applications of state-of-the-art spectral imaging and spectral LIDAR systems in the past decade have been summarized and presented. Furthermore, the progress in the development of compact spectral imaging and LIDAR sensing systems has also been reviewed. These systems are based on the nanophotonics technology. The most updated research works on subwavelength scale nanostructure-based functional devices for spectral imaging and optical frequency comb-based LIDAR sensing works have been reviewed. These compact systems will drive the translation of spectral imaging and LIDAR sensing from table-top toward portable solutions for consumer electronics applications. In addition, the future perspectives on nanophotonics-based spectral imaging and LIDAR sensing are also presented.

2018 ◽  
Vol 8 (3) ◽  
pp. 26
Author(s):  
Paul Milbredt ◽  
Efim Schick ◽  
Michael Hübner

Modern automotive control applications require a holistic time-sensitive development. Nowadays, this is achieved by technologies specifically designed for the automotive domain, like FlexRay, which offer a fault-tolerant time synchronization mechanism built into the protocol. Currently, the automotive industry adopts the Ethernet within the car, not only for embedding consumer electronics, but also as a fast and reliable backbone for control applications. Still, low-cost but highly reliable sensors connected over the traditional Controller Area Network (CAN) deliver data needed for autonomous driving. To fusion the data efficiently among all, a common timebase is required. The alternative would be oversampling, which uses more time and energy, e.g., at least double the perception rates of sensors. Ethernet and CAN do require the latter by default. Hence, a global synchronization mechanism eases tremendously the design of a low power automotive network and is the foundation of a transparent global clock. In this article, we present the first step: Synchronizing legacy FlexRay networks to the upcoming Ethernet backbone, which will contain a precise clock over the generalized Precision Time Protocol (gPTP) defined in IEEE 802.1AS. FlexRay then could still drive its strengths with deterministic transmission behavior and possibly also serve as a redundant technology for fail-operational system design.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.


Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5257
Author(s):  
Franc Dimc ◽  
Polona Pavlovčič-Prešeren ◽  
Matej Bažec

Robust autonomous driving, as long as it relies on satellite-based positioning, requires carrier-phase-based algorithms, among other types of data sources, to obtain precise and true positions, which is also primarily true for the use of GNSS geodetic receivers, but also increasingly true for mass-market devices. The experiment was conducted under line-of-sight conditions on a straight road during a period of no traffic. The receivers were positioned on the roof of a car travelling at low speed in the presence of a static jammer, while kinematic relative positioning was performed with the static reference base receiver. Interference mitigation techniques in the GNSS receivers used, which were unknown to the authors, were compared using (a) the observed carrier-to-noise power spectral density ratio as an indication of the receivers’ ability to improve signal quality, and (b) the post-processed position solutions based on RINEX-formatted data. The observed carrier-to-noise density generally exerts the expected dependencies and leaves space for comparisons of applied processing abilities in the receivers, while conclusions on the output data results comparison are limited due to the non-synchronized clocks of the receivers. According to our current and previous results, none of the GNSS receivers used in the experiments employs an effective type of complete mitigation technique adapted to the chirp jammer.


Author(s):  
Jiaqi Xu ◽  
Wei Sun ◽  
Kannan Srinivasan

RFID techniques have been extensively used in sensing systems due to their low cost. However, limited by the structural simplicity, collision is one key issue which is inevitable in RFID systems, thus limiting the accuracy and scalability of such sensing systems. Existing anti-collision techniques try to enable parallel decoding without sensing based applications in mind, which can not operate on COTS RFID systems. To address the issue, we propose COFFEE, which enables parallel channel estimation of COTS passive tags by harnessing the collision. We revisit the physical layer design of current standard. By exploiting the characteristics of low sampling rate and channel diversity of RFID tags, we separate the collided data and extract the channels of the collided tags. We also propose a tag identification algorithm which explores history channel information and identify the tags without decoding. COFFEE is compatible with current COTS RFID standards which can be applied to all RFID-based sensing systems without any modification on tag side. To evaluate the real world performance of our system, we build a prototype and conduct extensive experiments. The experimental results show that we can achieve up to 7.33x median time resolution gain for the best case and 3.42x median gain on average.


Author(s):  
Jonas Austerjost ◽  
Robert Söldner ◽  
Christoffer Edlund ◽  
Johan Trygg ◽  
David Pollard ◽  
...  

Machine vision is a powerful technology that has become increasingly popular and accurate during the last decade due to rapid advances in the field of machine learning. The majority of machine vision applications are currently found in consumer electronics, automotive applications, and quality control, yet the potential for bioprocessing applications is tremendous. For instance, detecting and controlling foam emergence is important for all upstream bioprocesses, but the lack of robust foam sensing often leads to batch failures from foam-outs or overaddition of antifoam agents. Here, we report a new low-cost, flexible, and reliable foam sensor concept for bioreactor applications. The concept applies convolutional neural networks (CNNs), a state-of-the-art machine learning system for image processing. The implemented method shows high accuracy for both binary foam detection (foam/no foam) and fine-grained classification of foam levels.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.


Author(s):  
Asmaa Zugari ◽  
Wael Abd Ellatif Ali ◽  
Mohammad Ahmad Salamin ◽  
El Mokhtar Hamham

In this paper, a compact reconfigurable tri-band/quad-band monopole antenna is presented. To achieve the multi-band behavior, two right-angled triangles were etched in a conventional rectangular patch, and a partial ground plane is used. Moreover, the proposed multi-band antenna is printed on a low cost FR4 epoxy with compact dimensions of 0.23[Formula: see text], where [Formula: see text] is calculated at the lowest resonance frequency. To provide frequency agility, a metal strip which acts as PIN diode was embedded in the frame of the modified patch. The tri-band/quad-band antenna performance in terms of reflection coefficient, radiation patterns, peak gain and efficiency was studied. The measured results are consistent with the simulated results for both cases. The simple structure and the compact size of the proposed antenna could make it a good candidate for multi-band wireless applications.


Author(s):  
Osamu Furuya ◽  
Hiroshi Kurabayashi

The response control techniques are mainly divided into two categories. One is a storey installation damper type using a damping element such as oil, elasto-plastic, viscoelastic, and so on. The other is an additional mass damper type such as a active and passive type tuned mass damper including a hybrid type. The device configuration of later damper type becomes larger into high-rise structure and long natural period structure because of increase of additional mass in the same case of mass ratio and necessary design stroke of moving mass. In generally, however, it is desired to be a compact size with a same vibration attenuation performance because of that there is a limitation of installation space for the device, and also it is important to be realize the application of the damper with low cost and with a necessary specification for damper performance. This study has been conducted to develop the passive tuned mass damper system using coil spring for long period structure considering a design indexes such as compact size, low cost and robustness. Although a coil spring has been well used by the tuned mass damper system as one way of solving a cost problem and performance stability, the problem of compact size still remains in case of the application to a long period structure. Multistage type is therefore proposed to the system in this time. Furthermore, the distributed TMD theory is applied to the system for robustness of the system. This paper summarizes from a basic theory to the application of proposed device to the real scale long period structure.


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