Efficient Silicon Nitride Grating Coupler with Silicon Reflector at Near-Infrared Wavelengths

2020 ◽  
Author(s):  
Min Liu ◽  
Daigao Chen ◽  
Xiao Hu ◽  
Peng Feng ◽  
Xi Xiao
Keyword(s):  
Silicon Nitride ◽  
Near Infrared ◽  
Grating Coupler ◽  
Infrared Wavelengths

scholarly journals Compact Silicon Nitride Arrayed Waveguide Gratings for Very Near-Infrared Wavelengths

2015 ◽  
Vol 27 (2) ◽  
pp. 137-140 ◽  
Author(s):  
Daan Martens ◽  
Ananth Z. Subramanian ◽  
Shibnath Pathak ◽  
Michael Vanslembrouck ◽  
Peter Bienstman ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Near Infrared ◽  
Arrayed Waveguide Gratings ◽  
Infrared Wavelengths ◽  
Waveguide Gratings ◽  
Arrayed Waveguide

scholarly journals Impact of ALD grown passivation layers on silicon nitride based integrated optic devices for very-near-infrared wavelengths

2014 ◽  
Vol 22 (5) ◽  
pp. 5684 ◽  
Author(s):  
Amit Khanna ◽  
Ananth Z Subramanian ◽  
Markus Häyrinen ◽  
Shankar Selvaraja ◽  
Peter Verheyen ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Near Infrared ◽  
Integrated Optic Devices ◽  
Passivation Layers ◽  
Infrared Wavelengths

Ultraflat and low dispersion in a horizontal silicon nitride slot waveguide at near-infrared wavelengths

2016 ◽  
Vol 55 (3) ◽  
pp. 037109 ◽  
Author(s):  
Lijuan Xu ◽  
Xiaochang Ni ◽  
Bowen Liu ◽  
Yanfeng Li ◽  
Minglie Hu
Keyword(s):  
Silicon Nitride ◽  
Near Infrared ◽  
Slot Waveguide ◽  
Infrared Wavelengths ◽  
Low Dispersion

Monolithic photonic integration for visible and short near-infrared wavelengths: technologies and platforms for bio and life science applications

2018 ◽  
Vol 7 (1-2) ◽  
pp. 57-65
Author(s):  
Marco A.G. Porcel ◽  
Iñigo Artundo ◽  
J. David Domenech ◽  
Douwe Geuzebroek ◽  
Rino Sunarto ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Integrated Circuits ◽  
Near Infrared ◽  
Life Science ◽  
State Of The Art ◽  
Photonic Integrated Circuits ◽  
Life Sciences ◽  
Photonic Integration ◽  
General Overview ◽  
Infrared Wavelengths

AbstractThis tutorial aims to provide a general overview on the state-of-the-art of photonic integrated circuits (PICs) in the visible and short near-infrared (NIR) wavelength ranges, mostly focusing in silicon nitride (SiN) substrates, and a guide to the necessary steps in the design toward the fabrication of such PICs. The focus is put on bio- and life sciences, given the adequacy and, thus, a large number of applications in this field.

scholarly journals Electromechanically reconfigurable optical nano-kirigami

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shanshan Chen ◽  
Zhiguang Liu ◽  
Huifeng Du ◽  
Chengchun Tang ◽  
Chang-Yin Ji ◽  
...  
Keyword(s):  
Near Infrared ◽  
Large Range ◽  
Three Dimensional ◽  
High Contrast ◽  
Si Substrate ◽  
High Modulation ◽  
Gold Nanostructure ◽  
Infrared Wavelengths ◽  
On Chip ◽  
Nano Electromechanical System

AbstractKirigami, with facile and automated fashion of three-dimensional (3D) transformations, offers an unconventional approach for realizing cutting-edge optical nano-electromechanical systems. Here, we demonstrate an on-chip and electromechanically reconfigurable nano-kirigami with optical functionalities. The nano-electromechanical system is built on an Au/SiO2/Si substrate and operated via attractive electrostatic forces between the top gold nanostructure and bottom silicon substrate. Large-range nano-kirigami like 3D deformations are clearly observed and reversibly engineered, with scalable pitch size down to 0.975 μm. Broadband nonresonant and narrowband resonant optical reconfigurations are achieved at visible and near-infrared wavelengths, respectively, with a high modulation contrast up to 494%. On-chip modulation of optical helicity is further demonstrated in submicron nano-kirigami at near-infrared wavelengths. Such small-size and high-contrast reconfigurable optical nano-kirigami provides advanced methodologies and platforms for versatile on-chip manipulation of light at nanoscale.

Spectral characteristics of leafy spurge (Euphorbia esula) leaves and flower bracts

Weed Science ◽  
2004 ◽  
Vol 52 (4) ◽  
pp. 492-497 ◽  
Author(s):  
E. Raymond Hunt ◽  
James E. McMurtrey ◽  
Amy E. Parker Williams ◽  
Lawrence A. Corp
Keyword(s):  
Remote Sensing ◽  
High Performance ◽  
Near Infrared ◽  
Spectral Characteristics ◽  
Leafy Spurge ◽  
Hyperspectral Remote Sensing ◽  
Total Carotenoids ◽  
Physiological Basis ◽  
Infrared Wavelengths ◽  
Pigment Concentrations

Leafy spurge can be detected during flowering with either aerial photography or hyperspectral remote sensing because of the distinctive yellow-green color of the flower bracts. The spectral characteristics of flower bracts and leaves were compared with pigment concentrations to determine the physiological basis of the remote sensing signature. Compared with leaves of leafy spurge, flower bracts had lower reflectance at blue wavelengths (400 to 500 nm), greater reflectance at green, yellow, and orange wavelengths (525 to 650 nm), and approximately equal reflectances at 680 nm (red) and at near-infrared wavelengths (725 to 850 nm). Pigments from leaves and flower bracts were extracted in dimethyl sulfoxide, and the pigment concentrations were determined spectrophotometrically. Carotenoid pigments were identified using high-performance liquid chromatography. Flower bracts had 84% less chlorophylla, 82% less chlorophyllb, and 44% less total carotenoids than leaves, thus absorptance by the flower bracts should be less and the reflectance should be greater at blue and red wavelengths. The carotenoid to chlorophyll ratio of the flower bracts was approximately 1:1, explaining the hue of the flower bracts but not the value of reflectance. The primary carotenoids were lutein, β-carotene, and β-cryptoxanthin in a 3.7:1.5:1 ratio for flower bracts and in a 4.8:1.3:1 ratio for leaves, respectively. There was 10.2 μg g−1fresh weight of colorless phytofluene present in the flower bracts and none in the leaves. The fluorescence spectrum indicated high blue, red, and far-red emission for leaves compared with flower bracts. Fluorescent emissions from leaves may contribute to the higher apparent leaf reflectance in the blue and red wavelength regions. The spectral characteristics of leafy spurge are important for constructing a well-documented spectral library that could be used with hyperspectral remote sensing.

scholarly journals Highly Efficient Near-Infrared Detector Based on Optically Resonant Dielectric Nanodisks

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 428
Author(s):  
Reza Masoudian Saadabad ◽  
Christian Pauly ◽  
Norbert Herschbach ◽  
Dragomir N. Neshev ◽  
Haroldo T. Hattori ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
High Speed ◽  
Near Infrared ◽  
Infrared Detector ◽  
High Quantum Efficiency ◽  
Fast Detection ◽  
High Quantum ◽  
Resonant Modes ◽  
Infrared Wavelengths ◽  
Dielectric Metasurface

Fast detection of near-infrared (NIR) photons with high responsivity remains a challenge for photodetectors. Germanium (Ge) photodetectors are widely used for near-infrared wavelengths but suffer from a trade-off between the speed of photodetection and quantum efficiency (or responsivity). To realize a high-speed detector with high quantum efficiency, a small-sized photodetector efficiently absorbing light is required. In this paper, we suggest a realization of a dielectric metasurface made of an array of subwavelength germanium PIN photodetectors. Due to the subwavelength size of each pixel, a high-speed photodetector with a bandwidth of 65 GHz has been achieved. At the same time, high quantum efficiency for near-infrared illumination can be obtained by the engineering of optical resonant modes to localize optical energy inside the intrinsic Ge disks. Furthermore, small junction capacitance and the possibility of zero/low bias operation have been shown. Our results show that all-dielectric metasurfaces can improve the performance of photodetectors.

scholarly journals Revised SED of the triple protostellar system VLA 1623−2417

2018 ◽  
Vol 615 ◽  
pp. L14 ◽  
Author(s):  
N. M. Murillo ◽  
D. Harsono ◽  
M. McClure ◽  
S.-P. Lai ◽  
M. R. Hogerheijde
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Gas Emission ◽  
Circumstellar Gas ◽  
Infrared Wavelengths ◽  
Previous Assumption

Context. VLA 1623−2417 is a triple protostellar system deeply embedded in Ophiuchus A. Sources A and B have a separation of 1.1″, making their study difficult beyond the submillimeter regime. Lack of circumstellar gas emission suggested that VLA 1623−2417 B has a very cold envelope and is much younger than source A, which is generally considered the prototypical Class 0 source. Aims. We explore the consequences of new ALMA Band 9 data on the spectral energy distribution (SED) of VLA 1623−2417 and their inferred nature. Methods. We constructed and analyzed the SED of each component in VLA 1623−2417 using dust continuum observations spanning from centimeter to near-infrared wavelengths. Results. The ALMA Band 9 data presented in this work show that the SED of VLA 1623−2417 B does not peak at 850 µm as previously expected, but instead presents the same shape as VLA 1623−2417 A at wavelengths shorter than 450 µm. Conclusions. The results presented in this work indicate that the previous assumption that the flux in Herschel and Spitzer observations is solely dominated by VLA 1623−2417 A is not valid, and instead, VLA 1623−2417 B most likely contributes a significant portion of the flux at λ < 450 µm. These results, however, do not explain the lack of circumstellar gas emission and puzzling nature of VLA 1623−2417 B.

Reflectance characteristics of cumulative defoliation of balsam fir

1988 ◽  
Vol 18 (8) ◽  
pp. 1008-1016 ◽  
Author(s):  
D. G. Leckie ◽  
P. M. Teillet ◽  
G. Fedosejevs ◽  
D. P. Ostaff
Keyword(s):  
Near Infrared ◽  
Spectral Characteristics ◽  
Broad Band ◽  
Integrating Sphere ◽  
Simple Relationship ◽  
Spectral Bands ◽  
Infrared Wavelengths ◽  
Remote Sensing Techniques ◽  
Middle Infrared ◽  
Airborne Sensors

Knowledge of the spectral characteristics of trees with varying degrees of needle loss is essential for developing remote sensing techniques for assessing defoliation. Spectra covering the range 400–2400 nm were acquired for single tree crowns suffering varying degrees of cumulative defoliation due to the spruce budworm (Choristoneurafumiferana (Clem.)), using a spectrometer mounted in the bucket of a boom truck. Spectra over the range 360–1100 nm were also obtained for the components of defoliated trees (i.e., needles, bare branches, and lichen), using a separate spectrometer and integrating sphere. Estimates of defoliation symptoms of each tree were made from the ground and above the tree. Changes in reflectance had a close and simple relationship with the defoliation symptoms measured. The spectral differences due to cumulative defoliation that were observed were broad-band features. The best spectral regions for differentiating levels of cumulative defoliation symptoms were the blue, red, shorter near-infrared wavelengths, and middle-infrared. Although currently available satellite and airborne sensors operate in these spectral regions, defoliation assessment may be improved by the use of optimized spectral bands.

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