scholarly journals Gold Enhanced Graphene-Based Photodetector on Optical Fiber with Ultrasensitivity over Near-Infrared Bands

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 124
Author(s):  
Wenguo Zhu ◽  
Songqing Yang ◽  
Huadan Zheng ◽  
Yuansong Zhan ◽  
Dongquan Li ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Near Infrared ◽  
Low Cost ◽  
Field Enhancement ◽  
Pmma Film ◽  
Infrared Band ◽  
Power Monitoring ◽  
Enhanced Absorption ◽  
Cost Efficient ◽  
Optic Communication

Graphene has been widely used in photodetectors; however its photoresponsivity is limited due to the intrinsic low absorption of graphene. To enhance the graphene absorption, a waveguide structure with an extended interaction length and plasmonic resonance with light field enhancement are often employed. However, the operation bandwidth is narrowed when this happens. Here, a novel graphene-based all-fiber photodetector (AFPD) was demonstrated with ultrahigh responsivity over a full near-infrared band. The AFPD benefits from the gold-enhanced absorption when an interdigitated Au electrode is fabricated onto a Graphene-PMMA film covered over a side-polished fiber (SFP). Interestingly, the AFPD shows a photoresponsivity of >1 × 104 A/W and an external quantum efficiency of >4.6 × 106% over a broadband region of 980–1620 nm. The proposed device provides a simple, low-cost, efficient, and robust way to detect optical fiber signals with intriguing capabilities in terms of distributed photodetection and on-line power monitoring, which is highly desirable for a fiber-optic communication system.

scholarly journals Plasmon-Enhanced Photoresponse of Self-Powered Si Nanoholes Photodetector by Metal Nanowires

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2460
Author(s):  
Pericle Varasteanu ◽  
Antonio Radoi ◽  
Oana Tutunaru ◽  
Anton Ficai ◽  
Razvan Pascu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Simulation Analysis ◽  
Field Enhancement ◽  
Metal Nanowires ◽  
Local Surface Plasmon Resonance ◽  
Resonance Effects ◽  
Enhanced Sensitivity ◽  
Infrared Spectral ◽  
Self Powered ◽  
Cost Efficient

In this work, we report the development of self-powered photodetectors that integrate silicon nanoholes (SiNHs) and four different types of metal nanowires (AgNWs, AuNWs, NiNWs, PtNWs) applied on the SiNHs’ surface using the solution processing method. The effectiveness of the proposed architectures is evidenced through extensive experimental and simulation analysis. The AgNWs/SiNHs device showed the highest photo-to-dark current ratio of 2.1 × 10−4, responsivity of 30 mA/W and detectivity of 2 × 1011 Jones along with the lowest noise equivalent power (NEP) parameter of 2.4 × 10−12 WHz−1/2 in the blue light region. Compared to the bare SiNHs device, the AuNWs/SiNHs device had significantly enhanced responsivity up to 15 mA/W, especially in the red and near-infrared spectral region. Intensity-modulated photovoltage spectroscopy (IMVS) measurements revealed that the AgNWs/SiNHs device generated the longest charge carrier lifetime at 470 nm, whereas the AuNWs/SiNHs showed the slowest recombination rate at 627 nm. Furthermore, numerical simulation confirmed the local field enhancement effects at the MeNWs and SiNHs interface. The study demonstrates a cost-efficient and scalable strategy to combine the superior light harvesting properties of SiNHs with the plasmonic absorption of metallic nanowires (MeNWs) towards enhanced sensitivity and spectral-selective photodetection induced by the local surface plasmon resonance effects.

scholarly journals The Use of UAV Mounted Sensors for Precise Detection of Bark Beetle Infestation

2019 ◽  
Vol 11 (13) ◽  
pp. 1561 ◽  
Author(s):  
Tomáš Klouček ◽  
Jan Komárek ◽  
Peter Surový ◽  
Karel Hrach ◽  
Přemysl Janata ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Near Infrared ◽  
Carbon Fixation ◽  
Water Cycle ◽  
Low Cost ◽  
Vegetation Indices ◽  
Nutrient Cycle ◽  
Visual Interpretation ◽  
Infrared Band ◽  
Individual Level

The bark beetle (Ips typographus) disturbance represents serious environmental and economic issue and presents a major challenge for forest management. A timely detection of bark beetle infestation is therefore necessary to reduce losses. Besides wood production, a bark beetle outbreak affects the forest ecosystem in many other ways including the water cycle, nutrient cycle, or carbon fixation. On that account, (not just) European temperate coniferous forests may become endangered ecosystems. Our study was performed in the unmanaged zone of the Krkonoše Mountains National Park in the northern part of the Czech Republic where the natural spreading of bark beetle is slow and, therefore, allow us to continuously monitor the infested trees that are, in contrast to managed forests, not being removed. The aim of this work is to evaluate possibilities of unmanned aerial vehicle (UAV)-mounted low-cost RGB and modified near-infrared sensors for detection of different stages of infested trees at the individual level, using a retrospective time series for recognition of still green but already infested trees (so-called green attack). A mosaic was created from the UAV imagery, radiometrically calibrated for surface reflectance, and five vegetation indices were calculated; the reference data about the stage of bark beetle infestation was obtained through a combination of field survey and visual interpretation of an orthomosaic. The differences of vegetation indices between infested and healthy trees over four time points were statistically evaluated and classified using the Maximum Likelihood classifier. Achieved results confirm our assumptions that it is possible to use a low-cost UAV-based sensor for detection of various stages of bark beetle infestation across seasons; with increasing time after infection, distinguishing infested trees from healthy ones grows easier. The best performance was achieved by the Greenness Index with overall accuracy of 78%–96% across the time periods. The performance of the indices based on near-infrared band was lower.

Discriminating forchlorfenuron-treated kiwifruits using a portable spectrometer and Vis/NIR diffuse transmittance spectroscopy technology

2017 ◽  
Vol 9 (28) ◽  
pp. 4207-4214 ◽  
Author(s):  
Dayang Liu ◽  
Qianqian Li ◽  
Weiqiang Li ◽  
Biao Yang ◽  
Wenchuan Guo
Keyword(s):  
Optical Fiber ◽  
Wavelength Range ◽  
Near Infrared ◽  
Low Cost ◽  
Fiber Probe ◽  
Charge Coupled Device ◽  
Optical Fiber Probe ◽  
Spectroscopy System

To explore the feasibility of low-cost miniaturized spectrometers in discriminating forchlorfenuron treated kiwifruits, a visible and near infrared (Vis/NIR) diffuse transmittance spectroscopy system was constructed by using a miniaturized charge coupled device (CCD) spectrometer in the wavelength range of 400–1100 nm and a self-developed optical fiber probe.

scholarly journals CO3D, A WORLDWIDE ONE ONE-METER ACCURACY DEM FOR 2025

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 299-304
Author(s):  
L. Lebègue ◽  
E. Cazala-Hourcade ◽  
F. Languille ◽  
S. Artigues ◽  
O. Melet
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Infrared Band ◽  
Automatic Production ◽  
Worldwide Production ◽  
Expected Performance ◽  
Absolute Height ◽  
Dem Accuracy ◽  
New Generation ◽  
2D And 3D

Abstract. The goal of the CO3D (Constellation Optique 3D) mission is the full-automatic production of a worldwide accurate DEM. CO3D is also a constellation of a new generation of low-cost optical satellites. The DEM accuracy is expected to be one meter in relative height and two meters in absolute height with a one-meter grid space. Each of the four satellites of the constellation will provide images with 0.50 m resolution in red, green, blue bands. A NIR (Near-InfraRed) band will also be available with a resolution close to 1 m. The satellites resource will be shared by, on one hand, the French institutions (government, scientists concerned by global Earth monitoring) who will have dedicated access and preferred price conditions, and on the other hand commercial customers interested in 2D and 3D products. The launch of the constellation is expected mid-2023 and 90 % of the DEM worldwide production should be reached by the end of 2025.Starting from an overview of the system characteristics and its main innovations, this paper presents the expected performance, the 2D and 3D products that should be available for the end-users and finally how they should be qualified.

scholarly journals Surface-Enhanced Absorption Spectroscopy for Optical Fiber Sensing

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 34
Author(s):  
Silje S. Fuglerud ◽  
Karolina Milenko ◽  
Astrid Aksnes ◽  
Dag R. Hjelme
Keyword(s):  
Optical Fiber ◽  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Real Life ◽  
Fiber Optic Probe ◽  
Enhanced Absorption ◽  
Au Film ◽  
Sensing Applications ◽  
Surface Enhanced ◽  
Visible Wavelengths

Visible and near-infrared spectroscopy are widely used for sensing applications but suffer from poor signal-to-noise ratios for the detection of compounds with low concentrations. Enhancement by surface plasmon resonance is a popular technique that can be utilized to increase the signal of absorption spectroscopy due to the increased near-field created close to the plasmons. Despite interest in surface-enhanced infrared absorption spectroscopy (SEIRAS), the method is usually applied in lab setups rather than real-life sensing situations. This study aimed to achieve enhanced absorption from plasmons on a fiber-optic probe and thus move closer to applications of SEIRAS. A tapered coreless fiber coated with a 100 nm Au film supported signal enhancement at visible wavelengths. An increase in absorption was shown for two dyes spanning concentrations from 5 × 10−8 mol/L to 8 × 10−4 mol/L: Rhodamine 6G and Crystal Violet. In the presence of the Au film, the absorbance signal was 2–3 times higher than from an identically tapered uncoated fiber. The results confirm that the concept of SEIRAS can be implemented on an optical fiber probe, enabling enhanced signal detection in remote sensing applications.

Detection of Methanol in Gasolines Using Near-Infrared Spectroscopy and an Optical Fiber

1987 ◽  
Vol 41 (8) ◽  
pp. 1388-1392 ◽  
Author(s):  
B. R. Buchanan ◽  
D. E. Honigs
Keyword(s):  
Infrared Spectroscopy ◽  
Linear Regression ◽  
Optical Fiber ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Low Cost ◽  
Weight Percent ◽  
Infrared Analysis ◽  
Stepwise Multiple Linear Regression ◽  
Hazardous Environments

Because of methanol's relatively low cost and its utility as an octane booster, a need to monitor the concentration of methanol in gasolines has evolved. Near-infrared analysis can be used to monitor methanol in gasolines with the use of optical fiber. If stepwise multiple linear regression is used, methanol can be predicted to within 0.25 weight percent. The use of an optical fiber lowers personnel and instrument exposure to hazardous environments and minimizes the risk of explosion. It is pointed out, however, that care must be taken in the prediction of future specimens. The differences between enumerative and analytical calibrations are also discussed.

scholarly journals A Tunable Triple-Band Near-Infrared Metamaterial Absorber Based on Au Nano-Cuboids Array

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 207 ◽  
Author(s):  
Feng Qin ◽  
Zeqiang Chen ◽  
Xifang Chen ◽  
Zao Yi ◽  
Weitang Yao ◽  
...  
Keyword(s):  
Surface Plasmons ◽  
Near Infrared ◽  
Structural Parameters ◽  
Fdtd Method ◽  
Field Enhancement ◽  
Metamaterial Absorber ◽  
Infrared Band ◽  
Perfect Absorption ◽  
Tunable Metamaterial ◽  
Triple Band

In this article, we present a design for a triple-band tunable metamaterial absorber with an Au nano-cuboids array, and undertake numerical research about its optical properties and local electromagnetic field enhancement. The proposed structure is investigated by the finite-difference time domain (FDTD) method, and we find that it has triple-band tunable perfect absorption peaks in the near infrared band (1000–2500 nm). We investigate some of structure parameters that influence the fields of surface plasmons (SP) resonances of the nano array structure. By adjusting the relevant structural parameters, we can accomplish the regulation of the surface plasmons resonance (SPR) peaks. In addition, the triple-band resonant wavelength of the absorber has good operational angle-polarization-tolerance. We believe that the excellent properties of our designed absorber have promising applications in plasma-enhanced photovoltaic, optical absorption switching and infrared modulator optical communication.

Programmable Multispectral Imager Development as Light Weight Payload for Low Cost Fixed Wing Unmanned Aerial Vehicles

2009 ◽  
Author(s):  
Yiding Han ◽  
Austin Jensen ◽  
Huifang Dou
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Near Infrared ◽  
Low Cost ◽  
Measurement Unit ◽  
Light Weight ◽  
Aerial Vehicles ◽  
System Module ◽  
Multispectral Remote Sensing ◽  
Cost Efficient ◽  
Multispectral Imager

In this paper, we have developed a light-weight and cost-efficient multispectral imager payload for low cost fixed wing UAVs (Unmanned Aerial Vehicles) that need no runway for takeoff and landing. The imager is band-reconfigurable, covering both visual (RGB) and near infrared (NIR) spectrum. The number of the RGB and NIR sensors is scalable, depending on the demands of specific applications. The UAV on-board microcomputer programs and controls the imager system, synchronizing each camera individually to capture airborne imagery. It also bridges the payload to the UAV system by sending and receiving message packages. The airborne imagery is time-stamped with the corresponding local and geodetic coordinates data measured by the onboard IMU (Inertia Measurement Unit) and GPS (Global Positioning System) module. Subsequently, the imagery will be orthorectified with the recorded geo-referencing data. The application of such imager system includes multispectral remote sensing, ground mapping, target recognition, etc. In this paper, we will outline the technologies, demonstrate our experimental results from actual UAV flight missions, and compare the results with our previous imager system.

scholarly journals 401 Assessing Crop Canopy Development Using a Digital, Red/Near-infrared Band Ratioing Camera

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 513A-513
Author(s):  
D.W. Peters ◽  
J.P. Mitchell ◽  
R.E. Plant ◽  
B.R. Hanson
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Crop Canopy ◽  
Analysis Software ◽  
Infrared Band ◽  
Crop Cover ◽  
Canopy Development ◽  
Lighting Conditions ◽  
Band Ratioing ◽  
Highly Correlated

Current methods of making crop cover estimates are time-consuming and tend to be highly variable. A low-cost, digital, red/near-infrared band ratioing camera (Dycam Inc., Chatsworth, Calif.) and accompanying software (S. Heinold, Woodland Hills, Calif.) were evaluated for estimating crop cover. The camera was tested using a set of images having leaf areas of known sizes with different crop, soil, and lighting conditions. In the field, camera-based crop cover estimates were compared to light bar measured estimates. Results indicate that the camera and image analysis software are capable of estimating percent crop cover over a range of soil, crop, and lighting environments. Camera-based crop cover estimates were highly correlated with light bar estimates (tomato r2 = 0.96, cotton r2 = 0.98). Under the conditions tested, the camera appears to be a useful tool for monitoring crop growth in the field.

scholarly journals Early detection of slight bruises in apples by cost-efficient near-infrared imaging

2022 ◽  
Vol 12 (1) ◽  
pp. 349
Author(s):  
Chanh-Nghiem Nguyen ◽  
Van-Linh Lam ◽  
Phuc-Hau Le ◽  
Huy-Thanh Ho ◽  
Chi-Ngon Nguyen
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Low Cost ◽  
Nir Spectroscopy ◽  
Global Market ◽  
Cost System ◽  
Nir Imaging ◽  
Thin Skin ◽  
Cost Efficient ◽  
Apple Fruits

Near-infrared (NIR) spectroscopy has been widely reported for its useful applications in assessing internal fruit qualities. Motivated by apple consumption in the global market, this study aims to evaluate the possibility of applying NIR imaging to detect slight bruises in apple fruits. A simple optical setup was designed, and low-cost system components were used to promote the future development of practical and cost-efficient devices. To evaluate the effectiveness of the proposed approach, slight bruises were created by a mild impact with a comparably low impact energy of only 0.081 Joules. Experimental results showed that 100% of bruises in Jazz and Gala apples were accurately detected immediately after bruising and within 3 hours of storage. Thus, it is promising to develop customer devices to detect slight bruises for not only apple fruits but also other fruits with soft and thin skin at their early damage stages.

Sign in / Sign up

Export Citation Format

Share Document