scholarly journals Physics of Nanostructure Design for Infrared Detectors

2021 ◽  
Author(s):  
Nibir Kumar Dhar ◽  
Samiran Ganguly ◽  
Srini Krishnamurthy
Keyword(s):  
Focal Plane ◽  
Infrared Detectors ◽  
Nanostructured Material ◽  
Absorption Efficiency ◽  
Cryogenic Cooling ◽  
Photon Absorption ◽  
Large Size ◽  
Low Dimensional ◽  
Dark Currents ◽  
Detector Design

Infrared detectors and focal plane array technologies are becoming ubiquitous in military, but are limited in the commercial sectors. The widespread commercial use of this technology is lacking because of the high cost and large size, weight and power. Most of these detectors require cryogenic cooling to minimize thermally generated dark currents, causing the size, weight, power and cost to increase significantly. Approaches using very thin detector design can minimize thermally generated dark current, but at a cost of lower absorption efficiency. There are emerging technologies in nanostructured material designs such as metasurfaces that can allow for increased photon absorption in a thin detector architecture. Ultra-thin and low-dimensional absorber materials may also provide unique engineering opportunities in detector design. This chapter discusses the physics and opportunities to increase the operating temperature using such techniques.

scholarly journals Optically Induced Field-Emission Source Based on Aligned Vertical Carbon Nanotube Arrays

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1810
Author(s):  
Mengjie Li ◽  
Qilong Wang ◽  
Ji Xu ◽  
Jian Zhang ◽  
Zhiyang Qi ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electric Field ◽  
Field Emission ◽  
Field Enhancement ◽  
Absorption Efficiency ◽  
Photon Absorption ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Induced Field ◽  
Optically Induced

Due to the high field enhancement factor and photon-absorption efficiency, carbon nanotubes (CNTs) have been widely used in optically induced field-emission as a cathode. Here, we report vertical carbon nanotube arrays (VCNTAs) that performed as high-density electron sources. A combination of high applied electric field and laser illumination made it possible to modulate the emission with laser pulses. When the bias electric field and laser power density increased, the emission process is sensitive to a power law of the laser intensity, which supports the emission mechanism of optically induced field emission followed by over-the-barrier emission. Furthermore, we determine a polarization dependence that exhibits a cosine behavior, which verifies the high possibility of optically induced field emission.

scholarly journals Investigation of Er3+ Ions Reinforced Zinc-Phosphate Glasses for Ionizing Radiation Shielding Applications

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6769
Author(s):  
Hesham M. H. Zakaly ◽  
Antoaneta Ene ◽  
Oyeleke I. Olarinoye ◽  
Samir Y. Marzouk ◽  
Shams H. Abdel-Hafez ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Glass Sample ◽  
Photoelectric Effect ◽  
Absorption Efficiency ◽  
Radiation Shielding ◽  
Phosphate Glasses ◽  
Photon Absorption ◽  
Buildup Factor ◽  
Slowing Down ◽  
Removal Cross Section

Melt quenching technique is used for preparing glasses with chemical formula (70P2O5)−(16−x)CdO−(14ZnO)−(xEr2O3), (x = 1–6 mol%) . These glasses were named Er1, Er2, Er3, Er4, Er5, and Er6, respectively. Photon buildup factors, fast neutron absorption, and electron stopping of the prepared glasses were examined. Glasses’ density was varied from 3.390 ± 0.003 for the Er1 glass sample to 3.412 ± 0.003 for the Er6 glass sample. The Buildup factor (BUF) spectra have relatively higher values in the Compton Scattering (CS) dominated areas compared to both Photoelectric effect (PE), and Pair Production (PP) dominated energy regions. The highest BUF appeared at the Er atom K-absorption edge, whose intensity increases as the molar concentration of Er2O3 in the glasses increases. The photon absorption efficiency (PAE) of the glasses increases according to the trend (PAE)Er1 < (PAE)Er2 < (PAE)Er3 < (PAE)Er4 < (PAE)Er5 < (PAE)Er6. Fast neutron removal cross-section, FNRC values of the glasses obtained via calculation varied from 0.1045–0.1039 cm−1 for Er1–Er6. Furthermore, the continuous slowing down approximation mode (CSDA) range enhances the kinetic energy of electrons for all glasses. Generally, results revealed that the investigated glasses could be applied for radiation shielding and dosimetric media.

Non-Resonant Two-Photon Absorption in Quantum Well Infrared Detectors

1994 ◽  
pp. 493-500 ◽  
Author(s):  
E. Dupont ◽  
P. B. Corkum ◽  
P. W. Dooley ◽  
H. C. Liu ◽  
P. H. Wilson ◽  
...  
Keyword(s):  
Quantum Well ◽  
Infrared Detectors ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon

scholarly journals Ultraprecise Photometry from Space: The MOST Microsat Mission

2000 ◽  
Vol 176 ◽  
pp. 74-75 ◽  
Author(s):  
J. M. Matthews ◽  
R. Kuschnig ◽  
G. A. H. Walker ◽  
J. Pazder ◽  
R. Johnson ◽  
...  
Keyword(s):  
Focal Plane ◽  
Large Size ◽  
Pointing Accuracy

AbstractMOST (Microvariability & Oscillations of STars / Microvariabilite et Oscillations STellaire) is a Canadian microsatellite mission intended to detect rapid photometric oscillations at theμmag level in stars brighter thanV∼ 6. This limit is set primarily by the 15-cm aperture of the MOST telescope. The small size and mass of the MOST bus (similar to a suitcase) sets a limit on the pointing accuracy of about ±10 arcsec. To achieve the required photometric precision under these conditions, the MOST focal plane features a set of Fabry microlenses which can spread the target starlight into a pupil image of the telescope onto a CCD. The large size (∼1600 pixels) and positional stability (±0.1 pixel) of these images makes MOST insensitive to CCD flat-fielding errors. MOST is currently on schedule to be launched in early 2002.

scholarly journals A focal plane detector design for a wide-band Laue-lens telescope

2005 ◽  
Vol 20 (1-3) ◽  
pp. 341-351 ◽  
Author(s):  
Ezio Caroli ◽  
Natalia Auricchio ◽  
Lorenzo Amati ◽  
Yuriy Bezsmolnyy ◽  
Carl Budtz-JøRgensen ◽  
...  
Keyword(s):  
Focal Plane ◽  
Wide Band ◽  
Laue Lens ◽  
Plane Detector ◽  
Detector Design ◽  
Focal Plane Detector

scholarly journals Simultaneous Control of Emission Localization and Two-Photon Absorption Efficiency in Dissymmetrical Chromophores

2010 ◽  
Vol 114 (9) ◽  
pp. 3152-3169 ◽  
Author(s):  
Claudine Katan ◽  
Marina Charlot ◽  
Olivier Mongin ◽  
Céline Le Droumaguet ◽  
Viatcheslav Jouikov ◽  
...  
Keyword(s):  
Absorption Efficiency ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Simultaneous Control
Sign in / Sign up

Export Citation Format

Share Document