Infrared Detectors

We offer Mercury Cadmium Telluride (MCT) detectors operating at or near room temperature.

Our basic product line features infrared detectors whose sensitive wavelength begins in the visible or around 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. For a 2.3 MB pdf covering most of our 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.

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.

Questions? Comments? Suggestions? Send email to the Webmaster at Boston Electronics.