Infrared Detectors and Photodetectors

This page contains:-

  • Dexter Thermopiles
  • Agiltron Lead Sulphide and Lead Selenide detectors
  • Centronic Photodetectors

Dexter Thermopiles for Infrared detectionDexter Thermopiles

Dexter Research Centre is a leader in the manufacture of high quality; high output Bismuth Antimony thin film and Silicon based infrared sensing thermopiles.
Thermopiles have a very wide spectral response from the UV to the far infra red and the wavelength of response can be limited by the addition of various filters or windows which can be either be built into the detector encapsulation or can be external.

Thermopile detectors are voltage-generating devices, which can be thought of as miniature arrays of thermocouple junctions. Our detectors are hermetically sealed in TO-18, to-5 or TO-8 transistor type packages, purged with inert gas and heat treated to ensure long term stability. Since the detector acts as pure resistance,
it generates no 1/f or microphonic noise, but only the Johnson noise of its own resistance.

Applications for thermopiles are limitless, but include:-

  • Non contact temperature measurement
  • Gas analysis
  • Hazard control including flame and explosion detection
  • Horizon Sensors

Thermopile Development Tool- Miniature Amplifier PCB

Available in three amplifier gains: 300, 500 and 1,000, this PCB includes a LM20 temperature sensor and 1.25V voltage reference. Although sized for single channel TO-5 packages, this amplifier is electrically compatible with all Dexter Research Center detectors, providing convenient buffering and pre-amplification of thermopile signal. The amplifier circuit board is impressively small (0.35” x 0.85”) and is designed around the AD8628 amplifier with ultra low offset (<1μV), low drift (<0.005μV/°C), and low bias current (100pA). The Mini Amp will operate on a 2.7V to 5.5V single supply, is chopper stabilized and has greatly reduced digital switching noise (0.5μVp-p from 0Hz to 10Hz, input referred).

For further information on Dexter Thermopiles click here.

 Lead Sulphide and Lead Selenide detectors are offered from Agiltron

Agiltron detector arrays

Agiltron is a leading producer of infrared detector products in the 1 to 5.5 micron wavelength region. Through the acquisition of SensArray Infrared, Agiltron is perfecting the proprietary technologies of fabricating lead salt detectors accumulated well over twenty years.

Lead salt detectors operate in photoconductive mode that become less resistant upon infrared radiation. They absorb energy selectively in the infrared bands of 1-3µm (PbS) and 3-5µm (PbSe), respectively. They are either operated at room temperature or thermoelectrially cooled, and can be equipped with integrated optical filters, pre-amplifiers or multiplexed amplifiers for arrays.

Typical applications include moisture measurement, gas sensing, and chemical analysis. All packages are 100% tested and available for immediate delivery. We offer standard and customized lead selenide (PbSe) and lead sulfide (PbS) infrared detectors and infrared arrays. These detectors are manufactured in accordance with ISO quality control standard. Agiltron offer extensive customer support.

For more information click on the links below:- (pdf files)

PbS detectors

PbS arrays

PbSe detectors

PbSe arrays

PbSe 2 x 2 detect


Centronic detectors

We are pleased to offer you an extensive range of Photodetectors. Brief summary is given below.
For more details on any of the various types just click on the appropriate heading and a pdf file will be downloaded in a new browser window.


New Series 91R mid infrared photodiodes

Centronic series 9IR photodiodes offer high sensitivity in the mid infrared. They are fabricated using GaAlAsSb/GaInAsSb heterostructures and are particularly well suited to applications in the 1.8-2.3 µm range. Packaging options include standard TO housings with or without thermoelectric cooling as well as chip on board. These devices are particularly well suited for applications based on absorption analysis.  
Applications include:-

  •  Gas sensing
  •  Optical pyrometry
  •  Flame measurement
  •  Eye safe designator detection
  •  Impurity detection
  •  Radiometry

Amplified Single Element Detector (ASD) Series

Centronic ASD Series integrate high performance single element photodiodes coupled to a high input impedance op-amp to create a low noise, high gain photodetector. Light falling on the active area of the photodiode causes the output voltage to swing positive with respect to ground. The photodiode has been optimised for sensitivity to near infrared wavelengths. The detector and circuit are hermetically sealed in an industry standard TO5 package with a flat glass window

General Purpose Silicon Sensors (Series 0)

Series 0 photodiodes are designed for operation at up to 30V reverse bias voltage for applications where low capacitance and high speed are important. These detectors are tailored for peak responsivity in the 780-950 nm range but are successfully used for pulsed applications throughout the spectral range from 430-1064 nm.

Blue and UV sensitive (Series 1)

Series 1 photodiodes offer a broadband spectral response extending into the UV region. The series is particularly intended for applications from 250 to 430 nm where high levels of illumination occur. The detectors may be operated with reverse bias up to 10 volts or in the photovoltaic mode for best signal to noise performance. And are particularly suitable for monitoring the operation of UV lamps.

High Speed Extended IR response (Series 3T)

3T series photodetectors are specifically designed for high speed, infra-red laser pulse detection. The detector structure designed to be fully depleted at 60 volts reverse bias, uses high resistivity silicon to achieve very low capacitance. The detectors offer high responsivity in the 800-1000 nm range but are equally suited to high speed application at longer wavelengths where maximum absolute responsivity is not as important as speed of response.

High Speed 1064nm Pulse sensing (Series 4X)

The 4X series of photodetectors are designed specifically for sensing high speed 1064 nm Nd YAG laser pulses. The detector structure is designed to be fully depleted at 150 volts reverse bias and offers high pulsed and DC responsivity at wavelengths up to 1100 nm coupled with an extremely low capacitance per unit area.

General Purpose Silicon Sensors (Series 5T)

The Centronic Series 5T detectors offer high blue sensitivity coupled with high shunt resistance and low dark leakage current. They are particularly suited to low light level applications from 430-900 nm where the highest signal to noise ratio is important. They may be operated photovoltaically or with a reverse bias of up to 12V where lower capacitance is needed. The 5T range provides the most economic solution for all applications where high speed of response above 800 nm is not critical.

UV Enhanced Detector (Series -7)

Series 7 Super UV Photodiodes compliment Series 1* and primarily designed for application in the 194-400 nm range where high shunt resistance and maximum sensitivity are needed. These detectors are available in a range of standard packages with a choice of window material to suit specific applications.

Eye Response Detectors (Series -E)

Centronic Series E photodetectors use the successful Series 5T chip together with high quality glass colour correcting filters. The resulting spectral response approximates to that of the human eye making this device ideal for use in general photometric applications

Photometric Response Detectors (Series -P)

The Centronic range of photometric detectors features the proven Series 5T chip combined with specially designed coloured glass filters installed in front of the detector chip. The detectors simulate closely the spectral response of the human eye and are intended for applications requiring measurement of light levels for medical, CRT displays, LED, LCD displays and photography and other applications where a close match to the CIE curve is required.

High Speed Detectors (BPX65)

The BPX65 family of detectors feature Centronic’s 1mm2 high speed, high sensitivity chip already successful in a wide variety of applications. The chip can be packaged in various forms suitable for fibre-optic communication, such as the AX65-RF (precisely centred, isolated, low chip to window spacing) a standard 2 or 3 lead TO18 or even epoxy encapsulated. It has also been used for encoder designs and with MIL SPEC release at the heart of advanced laser warning systems.

Ultra High Speed Detectors (AEPX)

The AEPX Series of photodiodes is offered in a range of small active area sizes suitable for high frequency fibre optic applications. These photodetectors take advantage of an epitaxial structure to achieve good high frequency response at operating voltages as low as 5 volts. The detectors may also be operated at higher bias levels up to 20 volts to achieve extremely fast pulsed response.