Tech Briefs Magazine - November 2021 - PIT-8

Thermal Imaging
tors, as powerful thermal im agers are
often only offered as standard products
with limited configurability.
The most effective thermal imagers
are tailored to overcome these challenges
and fill exactly this gap in the
market. Three areas where thermal
imager performance and ease of integration
are impacted are in the detector,
imager radiometric capabilities,
and the optical & electrical features
that are offered.
Advanced detector technology is
constantly reducing the pixel to pixel
spacing. This trend has been largely
driven by the cellphone industry and
has been most evident in visible cameras
but has helped improve thermal
imagers as well. The smaller the
detector pixel pitch - while maintaining
or improving sensitivity
(NETD) and noise performance -
the more effective a thermal imager
is. Smaller pitch generally supports
lower power, smaller mechanical
design constraints, and can usually
accommodate slower f/# optics (further
system size and weight savings).
Additionally, smaller pixel pitch
FPAs also allow for higher resolution
thermal imagers without a significant
penalty in size, weight, and power.
Radiometric performance properties
include expansion from Region
of Interest (ROI) only measurements
to full radiometric measurements on
every pixel of the FPA, enhanced
temperature measurement accuracy,
and extended target temperature
ranges.
Figure 2. Radiometric temperature measurement application thermal image.
Extreme market competition in
the gaming, virtual and augmented
reality, smartphone, telecom, and
autonomous vehicle industries has
dramatically increased electronic
processing capabilities while driving
down component footprint and
power consumption. As a result,
thermal imager designers have a
wider array of electronic component
options to choose from that
did not exist several years ago. The
broader variety of component
options also facilitates the design
and integration of more compact,
more efficient, and higher-performing
systems. Meanwhile, optical and
opto-mechanical fabrication techniques
have also advanced, which
allows designers to replace conventional
optics
with
nontraditional
optics
to further reduce the size and
8
Figure 3. Representative thermal Imager: The Jenoptik EVIDIR alpha 320 with 14 mm lens.
weight of optical subassemblies. These
broader industry trends, coupled with
continued detector and radiometric
advances within the thermal imaging
segment, can offer OEMs and system
integrators a wide range of flexibility
when the right thermal imager supports
these options.
Radiometric Thermal Imager
Market Sample
Table 1 summarizes a number of key
performance parameters for five current
radiometric thermal imagers with a
QVGA pixel format.
To illustrate some of the key performance
parameters identified in the
Photonics & Imaging Technology, November 2021
Cov
ToC
http://info.hotims.com/79419-902
Tech Briefs Magazine - November 2021

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