Pyroelectric linear arrays of the PYROSENS series from DIAS Infrared have been used successfully in spectroscopy and in temperature and radiation measurement devices for many years. The pyroelectric material used, lithium tantalate, enables very high signal-to-noise ratios and excellent temperature and long-term stability of the sensor properties.
The linear arrays have 128, 256 or 510 pixels with a pitch of 100 µm, 50 µm or 25 µm. The length of the pixels can be chosen depending on the application. A pixel length of 500 µm is often used in spectroscopy devices, while elements with a length of 100 µm are used in the DIAS line cameras PYROLINE for non-contact temperature measurement, for example. The pyroelectric chip with the sensor elements is located in a metal hermetic housing together with a CMOS readout circuit.
For high signal-to-noise ratios, the thickness of the pyroelectric chip must be very small. Through the use of ion beam etching technologies, elements as thin as less than 5 µm can be produced. An additional metal absorber layer on the radiation-sensitive elements is optionally possible, which guarantees high and spectrally uniform radiation absorption at wavelengths between 2 µm and 14 µm. So-called thermal insulation trenches can also optionally be present between the individual pixels, which minimize crosstalk of signals between the elements. This ensures high spatial resolution for temperature and radiation measurements and high spectral resolution for spectrometer applications.
In addition to many standard types of pyroelectric linear arrays, DIAS Infrared also offers customer and application-specific special solutions – including with adapted element geometry and special narrowband, broadband or linear variable filters as radiation entry windows. An example are particularly long 256-element line sensors with a pitch of 100 μm, ion beam etched thin chip and additional metal absorber for applications in compact spectrometers. The metal hermetic housing contains the pyroelectric chip, two readout circuits and a temperature sensor. These newly developed arrays are also available with thermal insulation trenches, so that particularly good signal-to-noise ratios are possible.
The linear arrays of the PYROSENS product range will be presented together with other infrared single and multi-element sensors as well as PYROSPOT pyrometers and PYROVIEW/PYROLINE thermal imaging cameras from May 9, 2023 at the Sensor+Test trade fair (Nuremberg, Stand 1-244, Hall 1).