OPERATION is easy to achieve: we routinely deliver your choice of
Vigo detector mouned on the exterior of a preamplifier (bandwidths
from 100 kHz to 250 MHz) that you bolt to a heat sink, cable to
a TE-cooler controller (that we also supply). You attach the
BNC cable to your display or recorder and you are in immediate operation!
These devices are
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!
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
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 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
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.
are exclusive agents in 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. Our thermopiles
are very competitive with those of Dexter Research and Perkin Elmer
8x8, 16x16, 32x31 and
64x62 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.
here for info on Imaging Arrays and Linear Arrays.
There are no competitors for these low cost devices.
here for info on Pyroelectric detectors. Heimann
pyroelectrics are competive with devices from InfraTec, from Perkin-Elmer
(now "Excellitas") and others.
here for info on Thermopiles for temp and gas concentration
sensing with 1 to 4 elements.
Heimann thermopiles are competitive with devices from Perkin-Elmer
(now "Excelitas"), Dexter Research and others.
here for a thermopile AMPLIFIER schematic.
Please watch this page
for a more complete description of the product line. Meanwhile,
here for our version of the Heimann Sensor product
lit. Also please visit www.heimannsensor.com.