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*The
News* The
*News* about
these
devices is very good and getting better. Vigo has changed
over production to new MOCVD equipment, which gives much better
control of material properties and device architecture. This
has lead to a rapid escalation of device sensitivity. Now
we can readily deliver TE-cooled photovoltaic devices with D*(10.6
microns) > 2.5x10E9 cm.hz1/2W-1 from DC to >50 MHz and TE-cooled
photoconductive devices with D*(12 microns) > 3x10E9 from >20
kHz to >15 Mhz. These device operate entirely without LN2
or any other cryogenics yet provide performance that is only a factor
of 3 to 5 less than cryogenic devices, and 10 to 1000 times better
than other non-cryogenic detectors!
How
do they do it? CLICK HERE for a brief presentation on the technology
and progress this represents.
Our basic product line
features infrared detectors whose sensitive wavelength begins in
the visible or around 2 microns. The longest wavelength they
measure varies; models are available that measure to 3 microns,
4 microns, 5 microns, 6 microns, 8, 10.6+ microns, 12 and 13 microns.
These detectors are optimized to specific wavelengths, and are appropriate
for use over a spectral range beginning at 1 micron for photoconductive
types and at 2.5 microms for photovoltaic types and dropping off
fairly sharply beyond their optimized wavelength. Also available
are several CO2 laser detectors, which have optimum operation
at a nominal wavelength of 10.6 microns. For
a pdf covering most of our IR quantum detectors, click here-
or email, fax or phone with a postal address and we will mail the
info.
Photoconductive vs. Photovoltaic
The detectors come in
photoconductive and photovoltaic types. Photovoltaic detectors
create a measurable voltage and current in response to photon bombardment,
much like a solar cell. Photoconductive devices change resistance
when photons come in. A low noise bias current must be used
to measure the resistance change. Photoconductive devices
tend to have somewhat higher signal (responsivity) and sometimes
slightly better signal-to-noise than photovoltaic equivalents when
operated at optimum frequencies. On the other hand, photoconductors
exhibit excess noise at low frequencies - called 1/f or flicker
noise, are often slower in frequency response, and the low noise
bias circuit costs money. For these reasons, the photovoltaic
devices are preferred for most applications. Nevertheless,
photoconductors can be made with larger active areas than PV devices,
so sometimes the need for larger area will prevail over the other
advantages of PV devices and make PC the right choice.
Sensitivity
Sensitivity of our detectors
can be increased by thermoelectric (TE) cooling or by the use of
an immersion lens, or both. TE-cooled detectors must be mounted
on a heat sink. Additionally, a TE-cooler power supply/controller
is necessary.
Spectrum
View detectors for the
spectral regions below.
Choosing a detector and,
if necessary, an associated preamp and TE cooling device can be
a confusing task. The following summaries identify some of
the issues to be aware of.
The following articles
offer assistance in selecting a detector and in proper care and
wiring of the detector.
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*The
News* The
*News* here is about our June 2007 appoinment as exclusive agents
for North America for Heimann. Their process is totally based
on silicon and specifically on silicon that can be made by standard
microcircuit processes, with resulting LOW COST and HIGH SOPHISTICATION.
In general, our thermal
detectors are used for non-contact temperature measurement and for
gas concentration sensing by absorption of IR radiation at a specific
wavelength in a gas cell. We encourage your inquires - please
tell us about the details of of your application, quantities invloved
and schedule on which samples and production quantities will be
needed. We will respond with our suggestions regarding detector
type (Thermopile of Pyroelectric) and other details.
IR
Camera!

8x8, 16x16 and 32x31 element
thermopile arrays are now available. The 16x16 and 32x31 are
immediately available in the form of a simple camera - but we do
not expect to sell cameras, this is only to make it easy for the
OEM customer to explore the device. What we really expect
is that a new class of products will be designed around these devices
(which are expected to be LOW COST in production quantities) in
which a simple visible image is overlaid or 'fused' with the IR
image to make a new generation of low cost thermal imagers.
Click
here for info on the demo-camera.
Click
here for array info.
Click
here for info on pyroelectric detectors.
Please watch this page
for a more complete description of the product line. Meanwhile,
click
here for our version of the Heimann Sensor product
lit. Also please visit www.heimannsensor.com.
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