scholarly journals Low-noise, high-brightness, tunable source of picosecond pulsed light in the near-infrared and visible

2011 ◽  
Vol 19 (25) ◽  
pp. 25337 ◽  
Author(s):  
Peter J. Mosley ◽  
Samuel A. Bateman ◽  
Laure Lavoute ◽  
William J. Wadsworth
Keyword(s):  
Near Infrared ◽  
Low Noise ◽  
Pulsed Light ◽  
High Brightness ◽  
Tunable Source

Infrared and Visible—Near Infrared Electroluminescence Developments for FA in AlGaN/GaN HEMTS on SiC

2010 ◽  
Author(s):  
M. Bouya ◽  
D. Carisetti ◽  
J.C. Clement ◽  
N. Malbert ◽  
N. Labat ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Near Infrared ◽  
High Electron Mobility Transistor ◽  
Low Noise ◽  
Civil Defense ◽  
Base Stations ◽  
Infrared Range ◽  
High Electron ◽  
Radar Applications ◽  
Gan Hemts

Abstract HEMT (High Electron Mobility Transistor) are playing a key role for power and RF low noise applications. They are crucial components for the development of base stations in the telecommunications networks and for civil, defense and space radar applications. As well as the improvement of the MMIC performances, the localization of the defects and the failure analysis of these devices are very challenging. To face these challenges, we have developed a complete approach, without degrading the component, based on front side failure analysis by standard (Visible-NIR) and Infrared (range of wavelength: 3-5 µm) electroluminescence techniques. Its complementarities and efficiency have been demonstrated through two case studies.

scholarly journals Uniform Spheres of α-NaYF4:RE3+ (RE=Eu, Tb, Ce, Er, and Tm): Template-Free Synthesis, Multi-Color Photoluminescence, and Their Application in Cellular Imaging

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 119
Author(s):  
Xiaofeng Fan ◽  
Laiqin Gu ◽  
Yiling Hu ◽  
Qi Zhu
Keyword(s):  
Near Infrared ◽  
Infrared Emission ◽  
Particle Sizes ◽  
Hydrothermal Processing ◽  
High Brightness ◽  
Luminescent Probes ◽  
Bio Imaging ◽  
Template Free ◽  
Near Infrared Emission

Uniformly dispersed luminescent probes with a high brightness and high resolution are desired in bio imaging fields. Here, ~100 nm sized and well-dispersed spheres of RE3+ doped α-NaYF4 (rare earth (RE) = Eu, Tb, Ce, Er, and Tm) have been facile synthesized through hydrothermal processing in the absence of a template, followed by a proper annealing. The processing window of the cubic structured spheres is wide, because the hydrothermal products are independent of the processing conditions, including reaction time and temperature. The original morphology and crystal structure can be well retained with a calcination temperature up to 600 °C. However, calcination gives rise to a reduction of particle sizes, as a result of the crystallite growth and densification. Under ultraviolet radiation, α-NaYF4:RE3+ spheres show characteristic f-f emissions of RE3+ (RE = Eu, Tb, Ce, Er, and Tm), and exhibit orange red, green, ultraviolet (UV), blue green, and blue emissions, respectively. Mainly because of the near-infrared emission at ~697 nm (5D0→7F4 transitions of Eu3+), the successful imaging of macrophages was achieved by NH2-NaYF4:Eu3+ probes, indicating their excellent imaging capacity for cells in vitro.

scholarly journals Sensitivity-Enhanced Fourier Transform Mid-Infrared Spectroscopy Using a Supercontinuum Laser Source

2020 ◽  
Vol 74 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Ivan Zorin ◽  
Jakob Kilgus ◽  
Kristina Duswald ◽  
Bernhard Lendl ◽  
Bettina Heise ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Path Length ◽  
Low Noise ◽  
Noise Levels ◽  
Mid Infrared ◽  
High Brightness ◽  
Thermal Emitters ◽  
Ft Ir ◽  
Supercontinuum Laser

Fourier transform infrared (FT-IR) spectrometers have been the dominant technology in the field of mid-infrared (mid-IR) spectroscopy for decades. Supercontinuum laser sources operating in the mid-IR spectral region now offer the potential to enrich the field of FT-IR spectroscopy due to their distinctive properties, such as high-brightness, broadband spectral coverage and enhanced stability. In our contribution, we introduce this advanced light source as a replacement for conventional thermal emitters. Furthermore, an approach to efficient coupling of pulsed mid-IR supercontinuum sources to FT-IR spectrometers is proposed and considered in detail. The experimental part is devoted to pulse-to-pulse energy fluctuations of the applied supercontinuum laser, performance of the system, as well as the noise and long-term stability. Comparative measurements performed with a conventional FT-IR instrument equipped with a thermal emitter illustrate that similar noise levels can be achieved with the supercontinuum-based system. The analytical performance of the supercontinuum-based FT-IR spectrometer was tested for a concentration series of aqueous formaldehyde solutions in a liquid flow cell (500 µm path length) and compared with the conventional FT-IR (130 µm path length). The results show a four-times-enhanced detection limit due to the extended path length enabled by the high brightness of the laser. In conclusion, FT-IR spectrometers equipped with novel broadband mid-IR supercontinuum lasers could outperform traditional systems providing superior performance, e.g., interaction path lengths formerly unattainable, while maintaining low noise levels known from highly stable thermal emitters.

scholarly journals Infrared detector activities at NASA Langley Research Center

2008 ◽  
Vol 1076 ◽  
Author(s):  
M. Nurul Abedin ◽  
Tamer F Refaat ◽  
Oleg V Sulima ◽  
Farzin Amzajerdian
Keyword(s):  
Remote Sensing ◽  
Near Infrared ◽  
Infrared Detector ◽  
Avalanche Photodiode ◽  
Low Noise ◽  
Focal Plane Arrays ◽  
Research Center ◽  
Single Element ◽  
Sensing Applications ◽  
Langley Research Center

ABSTRACTInfrared detector development and characterization at NASA Langley Research Center will be reviewed. These detectors were intended for ground, airborne, and space borne remote sensing applications. Discussion will be focused on recently developed single-element infrared detector and future development of near-infrared focal plane arrays (FPA). The FPA will be applied to next generation space-based instruments. These activities are based on phototransistor and avalanche photodiode technologies, which offer high internal gain and relatively low noise-equivalent-power. These novel devices will improve the sensitivity of active remote sensing instruments while eliminating the need for a high power laser transmitter.

scholarly journals Near-infrared probes based on fluorinated Si-rhodamine for live cell imaging

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10922-10927 ◽  
Author(s):  
Suxia Shen ◽  
Jingru Yu ◽  
Yaomin Lu ◽  
Shuchen Zhang ◽  
Xuegang Yi ◽  
...  
Keyword(s):  
Phenyl Ring ◽  
Live Cell Imaging ◽  
Near Infrared ◽  
Cell Imaging ◽  
Live Cell ◽  
Trifluoromethyl Group ◽  
High Brightness ◽  
Infrared Probes ◽  
Excellent Stability

Si-rhodamine probe with a trifluoromethyl group on the 2-position of the pendant phenyl ring retains high brightness and excellent stability in a harsh physiological environment.

scholarly journals A novel backpackable ice-penetrating radar system

2004 ◽  
Vol 50 (168) ◽  
pp. 147-150 ◽  
Author(s):  
Kenichi Matsuoka ◽  
Ryoji Saito ◽  
Renji Naruse
Keyword(s):  
Continuous Measurement ◽  
Pulse Amplitude ◽  
Low Noise ◽  
Radar System ◽  
Low Power Consumption ◽  
High Brightness ◽  
Bed Topography ◽  
Pulse Transmission ◽  
Valley Glacier ◽  
Noise Data

AbstractWe have developed a novel ice-penetrating radar system that can be carried on a backpack. Including batteries for a 3 hour continuous measurement, the total weight is 13 kg. In addition, it operates reliably down to –25°C, has a low power consumption of 24 W, and is semi-waterproof. The system has a built-in-one controller with a high-brightness display for reading data quickly, a receiver with 12-bit digitizing, and a 1 kV pulse transmitter in which the pulse amplitude varies by <0.2%. Optical communications between components provides low-noise data acquisition and allows synchronizing of the pulse transmission with sampling. Measurements with the system revealed the 300 m deep bed topography of a temperate valley glacier in the late ablation season.

scholarly journals A Complete Two-Dimensional Avalanche Photodiode Based on MoTe2−WS2−MoTe2 Heterojunctions With Ultralow Dark Current

2021 ◽  
Vol 8 ◽  
Author(s):  
Tenghui Ouyang ◽  
Ximiao Wang ◽  
Shaojing Liu ◽  
Huanjun Chen ◽  
Shaozhi Deng
Keyword(s):  
Dark Current ◽  
Near Infrared ◽  
Transition Metal Dichalcogenides ◽  
High Sensitivity ◽  
Avalanche Photodiode ◽  
Infrared Region ◽  
Low Noise ◽  
Two Dimensional ◽  
Device Structure ◽  
Avalanche Gain

Two-dimensional (2D)-material-based photodetectors have recently received great attention due to their potentials in developing ultrathin and highly compact devices. Avalanche photodiodes (APDs) are widely used in a variety of fields such as optical communications and bioimaging due to their fast responses and high sensitivities. However, conventional APDs based on bulk materials are limited by their relatively high dark current. One solution to tackle this issue is by employing nanomaterials and nanostructures as the active layers for APDs. In this study, we proposed and fabricated an atomically-thick APD based on heterojunctions formed by 2D transition metal dichalcogenides (TMDs). A typical device structure was formed by stacking a semiconducting monolayer WS2 onto two metallic few-layer MoTe2 flakes. Due to the Schottky barrier formed between the TMD layers and their atomic thicknesses, the dark current of the APD is greatly reduced down to 93 pA. In addition, the APD can operate through a broad spectral range from visible to near-infrared region, with a responsivity of 6.02 A/W, an external quantum efficiency of 1,406%, and an avalanche gain of 587. We believe that the 2D APD demonstrated here provides a feasible approach for developing all-2D optoelectronic devices with simultaneous high-sensitivity and low noise.

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