Infrared Detectors

Our basic product line features infrared detectors whose sensitive frequency begins at 1.5 microns.  The longest wavelength they measure varies; models are available that measure to 4 microns, 5 microns, 6 microns, 10.6+ microns, and 12 microns.  These detectors are optimized to specific wavelengths, and are appropriate for use over a spectral range beginning at 1.5 microns and dropping off fairly sharply beyond their optimized wavelength.  Also available are several CO₂ laser detectors, which have peak operation at a nominal wavelength of 10.6 microns.

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. For this reason, the photovoltaic devices are preferred for most applications.

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.

• Warning about TE-Cooled Detectors
• Vigo TE-Cooler Controllers

Spectrum

View detectors for the spectral regions below.

• 1.5 to 4 microns
• 1.5 to 5 microns
• 1.5 to 6 microns
• 1.5 to 10.6 microns
• 1.5 to 12 microns
• CO₂ laser detection (nominal 10.6 microns)
• thermal (heat) detection

The following articles offer assistance in selecting a detector and in proper care and wiring of the detector.

• Thermal Target Detection Using Vigo Detectors
• Predicting the Performance of a Photodetector
• Operation and Handling
• Pin Connections
• TO-8 and immersion lens detail