Tech Briefs Magazine - May 2021 - PIT-6
SWIR Line Scan Imaging Technology
Military Intelligence Surveillance and
Reconnaissance
The military relies on SWIR for intelligence, surveillance, and reconnaissance
(ISR). The US military uses SWIR for
low light imaging, target recognition,
and aerial reconnaissance. One way to
effectively implement aerial reconnaissance is with time delay and integration
(TDI); a summing technology for line
scan capture where a camera is mounted
under a plane and flown over an area to
map it. Because photons are in short
supply, the summing of multiple rows
provides a clear and complete picture.
Figure 2. SWIR can also help to differentiate products that are similar in color.
SWIR Options and the Future of
SWIR
Figure 3. Since SWIR can see through silicon, another application for SWIR imagers is solar panel
inspection.
SWIR multispectral systems are used
near the end of the sorting process
because they are so sensitive. They are
typically run twice or more to achieve up
to 99% purity of the recycled plastic
material.
Solar Panel Inspection
Since SWIR can see through silicon,
another application for SWIR imagers
is solar panel inspection (Figure 3).
With a global push toward more sustainable sources of energy, solar panels
have seen a significant increase in
adoption. Manufacturers need to make
sure their panels are free from defects,
cracks, or saw marks on the opposite
side of the wafer. In addition, SWIR
can be used to identify dead spots or
weak areas on a solar cell and help
prove the efficacy of the cell. Overall,
you wind up with a much higher quality product when SWIR is used for quality inspection. Many of these same
techniques can be used in semiconductor inspection.
Agriculture and Forestry
A lot of airborne imaging with SWIR is
related to agricultural or forestry applications. In agriculture, farmers need to
manage and respond to a seemingly
endless number of challenges to ensure
high quality and high yields. Weather,
invasive species, and disease can wreak
havoc on a crop. A farmer will see the
results as a crop starts to turn yellow and
wilt, but by that time it's often too late to
do anything to save the crop. With SWIR
imaging, scientists can precisely monitor
water absorption from the roots into the
leaves and make decisions on how to
treat those crops.
Data collected from imagery can also
provide farmers and foresters with the
insight they need to make decisions
related to additional irrigation or fertilizer, helping them to manage costs.
6
Although SWIR has many advantages,
the cost of SWIR systems is still relatively
high. As the technology is adopted more
widely and research and development
are continued, it is expected the costs
will decrease.
Some companies are looking at alternatives to the InGaAs sensor for SWIR
imaging. Quantum dot is one lowercost technology, but the cost is not as
low as anticipated. The biggest drawback of quantum dot technology is that
it has low quantum efficiency. So, its
sensitivity to light is at least a factor of
four lower than InGaAs. This means in
any place where photons are at a premium and the customer can afford it,
InGaAs is still the way to go. From our
perspective, to leverage quantum dot
technology, a customer would need to
be willing to give up sensitivity in
exchange for lower cost. They would
need to add much more illumination,
which would mean additional costs. To
date, there are few applications that
would benefit from this tradeoff.
Sony is also releasing their first
CMOS InGaAs SWIR detectors.
Although based on InGaAs, they are
taking InGaAs and mating it with the
CMOS readout circuit, pixel by pixel,
by replacing the indium metal with
copper. So, it's more of what you
would call a semiconductor kind of a
process, where they take in a wafer of
the CMOS circuit. They put InGaAs
chips on top and they actually fuse the
InGaAs and silicon via these copper
layers. This also allows for smaller pixels than can be achieved with indium
bump bonding, which ultimately can
also be about reducing cost for a given
resolution.
Photonics & Imaging Technology, May 2021
Cov
ToC
http://www.abpi.net/ntbpdfclicks/l.php?202105TBNAV
Tech Briefs Magazine - May 2021
Table of Contents for the Digital Edition of Tech Briefs Magazine - May 2021
Tech Briefs Magazine - May 2021 - Intro
Tech Briefs Magazine - May 2021 - Sponsor
Tech Briefs Magazine - May 2021 - Cov1
Tech Briefs Magazine - May 2021 - Cov2
Tech Briefs Magazine - May 2021 - 1
Tech Briefs Magazine - May 2021 - 2
Tech Briefs Magazine - May 2021 - 3
Tech Briefs Magazine - May 2021 - 4
Tech Briefs Magazine - May 2021 - 5
Tech Briefs Magazine - May 2021 - 6
Tech Briefs Magazine - May 2021 - 7
Tech Briefs Magazine - May 2021 - 8
Tech Briefs Magazine - May 2021 - 9
Tech Briefs Magazine - May 2021 - 10
Tech Briefs Magazine - May 2021 - 11
Tech Briefs Magazine - May 2021 - 12
Tech Briefs Magazine - May 2021 - 13
Tech Briefs Magazine - May 2021 - 14
Tech Briefs Magazine - May 2021 - 15
Tech Briefs Magazine - May 2021 - 16
Tech Briefs Magazine - May 2021 - 17
Tech Briefs Magazine - May 2021 - 18
Tech Briefs Magazine - May 2021 - 19
Tech Briefs Magazine - May 2021 - 20
Tech Briefs Magazine - May 2021 - 21
Tech Briefs Magazine - May 2021 - 22
Tech Briefs Magazine - May 2021 - 23
Tech Briefs Magazine - May 2021 - 24
Tech Briefs Magazine - May 2021 - 25
Tech Briefs Magazine - May 2021 - 26
Tech Briefs Magazine - May 2021 - 27
Tech Briefs Magazine - May 2021 - 28
Tech Briefs Magazine - May 2021 - 29
Tech Briefs Magazine - May 2021 - 30
Tech Briefs Magazine - May 2021 - 31
Tech Briefs Magazine - May 2021 - 32
Tech Briefs Magazine - May 2021 - 33
Tech Briefs Magazine - May 2021 - 34
Tech Briefs Magazine - May 2021 - 35
Tech Briefs Magazine - May 2021 - 36
Tech Briefs Magazine - May 2021 - 37
Tech Briefs Magazine - May 2021 - 38
Tech Briefs Magazine - May 2021 - 39
Tech Briefs Magazine - May 2021 - 40
Tech Briefs Magazine - May 2021 - 41
Tech Briefs Magazine - May 2021 - 42
Tech Briefs Magazine - May 2021 - 43
Tech Briefs Magazine - May 2021 - 44
Tech Briefs Magazine - May 2021 - 45
Tech Briefs Magazine - May 2021 - 46
Tech Briefs Magazine - May 2021 - 47
Tech Briefs Magazine - May 2021 - 48
Tech Briefs Magazine - May 2021 - 49
Tech Briefs Magazine - May 2021 - 50
Tech Briefs Magazine - May 2021 - 51
Tech Briefs Magazine - May 2021 - 52
Tech Briefs Magazine - May 2021 - 53
Tech Briefs Magazine - May 2021 - 54
Tech Briefs Magazine - May 2021 - 55
Tech Briefs Magazine - May 2021 - 56
Tech Briefs Magazine - May 2021 - Cov3
Tech Briefs Magazine - May 2021 - Cov4
Tech Briefs Magazine - May 2021 - PIT-Cov1
Tech Briefs Magazine - May 2021 - PIT-Cov2
Tech Briefs Magazine - May 2021 - PIT-1
Tech Briefs Magazine - May 2021 - PIT-2
Tech Briefs Magazine - May 2021 - PIT-3
Tech Briefs Magazine - May 2021 - PIT-4
Tech Briefs Magazine - May 2021 - PIT-5
Tech Briefs Magazine - May 2021 - PIT-6
Tech Briefs Magazine - May 2021 - PIT-7
Tech Briefs Magazine - May 2021 - PIT-8
Tech Briefs Magazine - May 2021 - PIT-9
Tech Briefs Magazine - May 2021 - PIT-10
Tech Briefs Magazine - May 2021 - PIT-11
Tech Briefs Magazine - May 2021 - PIT-12
Tech Briefs Magazine - May 2021 - PIT-13
Tech Briefs Magazine - May 2021 - PIT-14
Tech Briefs Magazine - May 2021 - PIT-15
Tech Briefs Magazine - May 2021 - PIT-16
Tech Briefs Magazine - May 2021 - PIT-17
Tech Briefs Magazine - May 2021 - PIT-18
Tech Briefs Magazine - May 2021 - PIT-19
Tech Briefs Magazine - May 2021 - PIT-20
Tech Briefs Magazine - May 2021 - PIT-21
Tech Briefs Magazine - May 2021 - PIT-22
Tech Briefs Magazine - May 2021 - PIT-23
Tech Briefs Magazine - May 2021 - PIT-24
Tech Briefs Magazine - May 2021 - PIT-25
Tech Briefs Magazine - May 2021 - PIT-26
Tech Briefs Magazine - May 2021 - PIT-27
Tech Briefs Magazine - May 2021 - PIT-28
Tech Briefs Magazine - May 2021 - PIT-Cov3
Tech Briefs Magazine - May 2021 - PIT-Cov4
https://www.nxtbook.com/smg/techbriefs/25TB02
https://www.nxtbook.com/smg/techbriefs/25TB01
https://www.nxtbook.com/smg/techbriefs/24TB12
https://www.nxtbook.com/smg/techbriefs/24TB11
https://www.nxtbook.com/smg/techbriefs/24TB10
https://www.nxtbook.com/smg/techbriefs/24TB09B
https://www.nxtbook.com/smg/techbriefs/24TB09
https://www.nxtbook.com/smg/techbriefs/24TB08
https://www.nxtbook.com/smg/techbriefs/24TB07
https://www.nxtbook.com/smg/techbriefs/24TB06
https://www.nxtbook.com/smg/techbriefs/24TB05B
https://www.nxtbook.com/smg/techbriefs/24TB05
https://www.nxtbook.com/smg/techbriefs/24TB04
https://www.nxtbook.com/smg/techbriefs/24TB03
https://www.nxtbook.com/smg/techbriefs/24TB02
https://www.nxtbook.com/smg/techbriefs/24TB01
https://www.nxtbook.com/smg/techbriefs/23TB12
https://www.nxtbook.com/smg/techbriefs/23TB11
https://www.nxtbook.com/smg/techbriefs/23TB10
https://www.nxtbook.com/smg/techbriefs/23TB09
https://www.nxtbook.com/smg/techbriefs/23TB08
https://www.nxtbook.com/smg/techbriefs/23TB07
https://www.nxtbook.com/smg/techbriefs/23TB06
https://www.nxtbook.com/smg/techbriefs/23TB05
https://www.nxtbook.com/smg/techbriefs/23TB04
https://www.nxtbook.com/smg/techbriefs/23TB03
https://www.nxtbook.com/smg/techbriefs/23TB02
https://www.nxtbook.com/smg/techbriefs/23TB01
https://www.nxtbook.com/smg/Testing/22TB12
https://www.nxtbook.com/smg/techbriefs/22TB12
https://www.nxtbook.com/smg/techbriefs/22TB11
https://www.nxtbook.com/smg/techbriefs/22TB10
https://www.nxtbook.com/smg/techbriefs/22TB09
https://www.nxtbook.com/smg/techbriefs/22TB08
https://www.nxtbook.com/smg/techbriefs/22TB07
https://www.nxtbook.com/smg/techbriefs/22TB06
https://www.nxtbook.com/smg/techbriefs/22TB05-P
https://www.nxtbook.com/smg/techbriefs/22TB05-D
https://www.nxtbook.com/smg/techbriefs/22TB04
https://www.nxtbook.com/smg/techbriefs/22TB03
https://www.nxtbook.com/smg/techbriefs/22TB02
https://www.nxtbook.com/smg/techbriefs/22TB01
https://www.nxtbook.com/smg/techbriefs/21TB12
https://www.nxtbook.com/smg/techbriefs/21TB11
https://www.nxtbook.com/smg/techbriefs/21TB10
https://www.nxtbook.com/smg/techbriefs/21TB09
https://www.nxtbook.com/smg/techbriefs/21TB08
https://www.nxtbook.com/smg/techbriefs/21TB07
https://www.nxtbook.com/smg/techbriefs/21TB06
https://www.nxtbook.com/smg/techbriefs/21TB05
https://www.nxtbook.com/smg/techbriefs/21TB04
https://www.nxtbook.com/smg/techbriefs/21BT03
https://www.nxtbook.com/smg/techbriefs/21TB02
https://www.nxtbookmedia.com