國立虎尾科技大學 |

High Absorption Per Unit Thermal Mass Subwavelength Perforated Membrane as Uncooled Thermal Infrared Detector.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	High Absorption Per Unit Thermal Mass Subwavelength Perforated Membrane as Uncooled Thermal Infrared Detector./
Author:	Das, Avijit.
Description:	1 online resource (151 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 84-09, Section: B.
Contained By:	Dissertations Abstracts International84-09B.
Subject:	Electrical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9798377600541

High Absorption Per Unit Thermal Mass Subwavelength Perforated Membrane as Uncooled Thermal Infrared Detector.
Das, Avijit.

High Absorption Per Unit Thermal Mass Subwavelength Perforated Membrane as Uncooled Thermal Infrared Detector. - 1 online resource (151 pages)

Source: Dissertations Abstracts International, Volume: 84-09, Section: B.

Thesis (Ph.D.)--University of Minnesota, 2023.

Includes bibliographical references

In the first project, a theoretical and experimental investigation of photon diﬀusion is discussed in highly absorbing microscale graphite. A Nd:YAG continuous wave laser is used to heat the graphite samples with thicknesses of 40 µm and 100 µm. Optical intensities of 10 kW cm−2 and 20 kW cm−2 are used in laser heating. The graphite samples are heated to temperatures of thousands of kelvins within milliseconds, which are recorded by a 2-color, high-speed pyrometer. To compare the observed temperatures, the diﬀerential equation of heat conduction is solved across the samples with proper initial and boundary conditions. In addition to lattice vibrations, photon diﬀusion is incorporated into the analytical model of thermal conductivity for solving the heat equation. The numerical simulations showed close matching between experiment and theory only when including the photon diﬀusion equations and existing material properties data found in the previously published works with no fitting constants. The results indicate that the commonly overlooked mechanism of photon diﬀusion dominates the heat transfer of many microscale structures near their evaporation temperatures. In addition, the treatment explains the discrepancies between thermal conductivity measurements and theory that were previously described in the scientifc literature.In the second project, a subwavelength perforated metamaterial absorber is developed for a maximum absorption-to-thermal mass ratio to construct an uncooled thermal infrared (λ∼8−12 µm) detector operating at a time constant of ∼7.7 ms, faster than the video frame rates, with a noise equivalent temperature diﬀerence (NETD) of 4.5 mKand a detectivity of 3.8x109cm√Hz/W. The designed metamaterial absorber consists of Ti, SiNx, and Ni nanoscale films with an overall fill factor of ∼28%, where subwavelength interference and Fabry Perot resonance induce an absorption per unit mass of approximately 1.3−27.6 times higher than the previously reported infrared absorbers. We read out the fabricated detector optically via Mach Zehnder interferometer.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798377600541Subjects--Topical Terms:

596380
Electrical engineering.
Subjects--Index Terms:

Absorption per unit massIndex Terms--Genre/Form:

554714
Electronic books.

High Absorption Per Unit Thermal Mass Subwavelength Perforated Membrane as Uncooled Thermal Infrared Detector.
LDR:03746ntm a22004577 4500 001 1143720
005 20240517104935.5
006 m o d
007 cr mn ---uuuuu
008 250605s2023 xx obm 000 0 eng d
020 $a 9798377600541
035 $a (MiAaPQ)AAI30248652
035 $a AAI30248652
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Das, Avijit. $3 1468500
245 1 0 $a High Absorption Per Unit Thermal Mass Subwavelength Perforated Membrane as Uncooled Thermal Infrared Detector.
264 0 $c 2023
300 $a 1 online resource (151 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 84-09, Section: B.
500 $a Advisor: Talghader, Joseph J.
502 $a Thesis (Ph.D.)--University of Minnesota, 2023.
504 $a Includes bibliographical references
520 $a In the first project, a theoretical and experimental investigation of photon diﬀusion is discussed in highly absorbing microscale graphite. A Nd:YAG continuous wave laser is used to heat the graphite samples with thicknesses of 40 µm and 100 µm. Optical intensities of 10 kW cm−2 and 20 kW cm−2 are used in laser heating. The graphite samples are heated to temperatures of thousands of kelvins within milliseconds, which are recorded by a 2-color, high-speed pyrometer. To compare the observed temperatures, the diﬀerential equation of heat conduction is solved across the samples with proper initial and boundary conditions. In addition to lattice vibrations, photon diﬀusion is incorporated into the analytical model of thermal conductivity for solving the heat equation. The numerical simulations showed close matching between experiment and theory only when including the photon diﬀusion equations and existing material properties data found in the previously published works with no fitting constants. The results indicate that the commonly overlooked mechanism of photon diﬀusion dominates the heat transfer of many microscale structures near their evaporation temperatures. In addition, the treatment explains the discrepancies between thermal conductivity measurements and theory that were previously described in the scientifc literature.In the second project, a subwavelength perforated metamaterial absorber is developed for a maximum absorption-to-thermal mass ratio to construct an uncooled thermal infrared (λ∼8−12 µm) detector operating at a time constant of ∼7.7 ms, faster than the video frame rates, with a noise equivalent temperature diﬀerence (NETD) of 4.5 mKand a detectivity of 3.8x109cm√Hz/W. The designed metamaterial absorber consists of Ti, SiNx, and Ni nanoscale films with an overall fill factor of ∼28%, where subwavelength interference and Fabry Perot resonance induce an absorption per unit mass of approximately 1.3−27.6 times higher than the previously reported infrared absorbers. We read out the fabricated detector optically via Mach Zehnder interferometer.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2024
538 $a Mode of access: World Wide Web
650 4 $a Electrical engineering. $3 596380
650 4 $a Condensed matter physics. $3 1148471
650 4 $a Remote sensing. $3 557272
653 $a Absorption per unit mass
653 $a Detectivity
653 $a Effective medium
653 $a Noise equivalent temperature difference
653 $a Perforated metamaterial
653 $a Uncooled thermal detector
653 $a Thermal mass
653 $a Perforated membrane
653 $a Infrared detector
653 $a High absorption
655 7 $a Electronic books. $2 local $3 554714
690 $a 0544
690 $a 0611
690 $a 0799
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a University of Minnesota. $b Electrical/Computer Engineering. $3 1182326
773 0 $t Dissertations Abstracts International $g 84-09B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=30248652 $z click for full text (PQDT)