What are the detectors used in IR spectroscopy?

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. Bolometers and microbolometers are based on changes in resistance. Thermocouples and thermopiles use the thermoelectric effect.

How does an infrared detector work?

Active infrared sensors work with radar technology and they both emit and receive infrared radiation. This radiation hits the objects nearby and bounces back to the receiver of the device. Through this technology, the sensor can not only detect movement in an environment but also how far the object is from the device.

What is InGaAs detector?

InGaAs photodiodes for near-infrared light detection. Features include high speed, high sensitivity, low noise, and spectral responses ranging from 0.5 μm to 2.6 μm. Suitable for a wide range of applications including optical communication, analysis, and measurement.

What detector means?

Definition of detector : one that detects: such as. a : a device for detecting the presence of electromagnetic waves or of radioactivity. b : a rectifier of high-frequency current used especially for extracting the intelligence from a radio signal.

What are the detectors used in HPLC?

Lesson 6: Detectors for HPLC

UV, VIS, and PDA Detectors. Refractive-Index Detector.
UV, VIS, and PDA Detectors.
Refractive-Index Detector.
Evaporative Light Scattering Detector.
Multi-Angle Light Scattering Detector.
Mass Spectrometer.
Conductivity Detector.
Fluorescence Detector.

Why is InGaAs so expensive?

Most infrared fabs don’t run that many InGaAs wafers in a year, let alone a month, limiting their statistical process control and ability to have high yield which is one of the many reasons InGaAs detector arrays are so expensive.

Is InGaAs a semiconductor?

InGaAs is a room-temperature semiconductor with applications in electronics and photonics. The principal importance of GaInAs is its application as a high-speed, high sensitivity photodetector of choice for optical fiber telecommunications.

What is a photoconductive detector used for?

They are mostly used for detecting infrared light with particularly long wavelength, and are dominant in that applications beyond 20 μm. A photoconductive detector can simply consist of a piece of semiconductor material with two attached metallic electrodes for sensing the resistance.

What are photodetectors and how do they work?

Photoconductive detectors are a type of photodetectors which are based on photoconductive semiconductor materials. Here, the absorption of incident light creates non-equilibrium electrical carriers, and that reduces the electrical resistance across two electrodes.

How does noise affect the output signal of a photoconductive detector?

Different types of noise can affect the output signal of a photoconductive detector: There is a thermal noise, also called Johnson noise, arising from the thermal movement of carriers. Its strength depends on the resistance and the operation temperature. There is noise arising from generation and recombination of carriers.

When is it possible to detect a photon with a detector?

This is possible only when the photon energy is above the band gap energy, i.e., for a sufficiently short optical wavelengths. For example, lead salt, cadmium sulfide and mercury cadmium selenide detectors are based on that operation principle.