How does MCT detector work?

How does MCT detector work?

The MCT detector is a semiconductor and the electrons present in it absorb IR light and move from valence band to conduction band. These electrons in the conduction band generate an electrical current proportional to the IR intensity.

What is MCT detector?

The MCT (Mercury-Cadmium-Telluride) IR (infrared) Detector Module is a thermoelectrically cooled detector element and preamplifier package optimized for acquiring spectral data with the LaserTune Quantum Cascade Laser (QCL) source.

Why do infrared detectors require cooling?

One of the inherent requirements of quantum detectors is that the sensor must be cooled for operation, typically to between 50 K and 200 K. The reason cooling is necessary is that the sensors either will not operate at room temperature or because the performance is greatly improved at lower temperatures.

How does DTGS detector work?

In a DTGS detector a change in the intensity of IR radiation striking the detector will cause a proportional change in temperature. Change in temperature in turn will cause change in the dielectric constant of DTGS and hence its capacitance. This change in capacitance is measured as the detector response in voltage.

Why Liquid nitrogen is used in FTIR?

We will use liquid nitrogen (LN2) to cool the detectors on the FTIR spectrometer. It is also used to cool the detectors on some Scanning Electron Microscopes. We will just be transferring LN2 from the dewar into a smaller container, then into the FTIR.

What is detected by FTIR?

Fourier Transform Infrared Spectroscopy (FTIR) identifies chemical bonds in a molecule by producing an infrared absorption spectrum. The spectra produce a profile of the sample, a distinctive molecular fingerprint that can be used to screen and scan samples for many different components.

What is a detector of infrared radiation?

An infrared detector is a detector that reacts to infrared (IR) radiation. The two main types of detectors are thermal and photonic (photodetectors). The thermal effects of the incident IR radiation can be followed through many temperature dependent phenomena. Incident IR photons can cause electronic excitations.

What is pyroelectric detector?

A Pyroelectric detector is an infrared sensitive optoelectronic component which are specifically used for detecting electromagnetic radiation in a wavelength range from 2 to 14 µm. A receiver chip of a pyroelectric infrared detector manufactured by InfraTec consists of single-crystalline lithium tantalate.

Why are infrared detectors shielded and kept at low temperatures?

An infrared detector is protected from thermal background radiation outside its optical field of view. Cold shields are typically used in IR optical devices for military, scientific and industrial applications to protect IR sensors from stray IR radiation (lowering noise figures).

Why an IR spectrometer is often purged with dry nitrogen?

Purging the FTIR spectrometer with clean, dry carbon dioxide-free gas will improve the signal to noise ratio (SNR) by decreasing the level of background noise.

Is MCT really better than InSb?

The seriousness of this issue may have been exaggerated; the actual operability difference between MCT and InSb was always under 0.1%. Nevertheless, MCT’s operability is now at 99.5% — equal to or better than InSb.

What are InSb Photovoltaic detectors?

InSb photovoltaic detectors are high-speed, low-noise infrared detectors that deliver high sensitivity in the so-called atmospheric window between 3 and 5 μm. The infrared light in the 5 μm band can be detected with peak sensitivity and high response speed.

What are the disadvantages of MCT detector?

Disadvantages of MCT detectors are that most of them have a narrow bandwidth based on their composition and they saturate very easily. They are very sensitive to temperature and require cooling with liquid nitrogen. Improper cooling will result in a noisy signal. MCT detectors cost more than DTGS detectors.

What size InSb detectors are available?

Custom Detectors: InSb detectors in any size up to 7mm diameter and in any configuration can be provided on a custom basis. Contact Judson for specifications for linear position sensors, quad cells, and two-color (sandwich) detectors.