The LVF-32E is a compact spectral analyser able to detect and identify various types of polymers. We demonstrate its functionality in the 3 – 4 μm wavelength range for detection of polystyrene (PS), polyethylene (PE) and polyimide (PI) thin foils.

Spectral selectivity is achieved by using an uncooled 32-element HgCdTe (MCT) linear photodiode array in conjunction with a thin-film linear-variable filter which is placed in close proximity. In effect, each pixel of the array has a different, narrow spectral response.

To determine the composition of a measured sample, the LVF-32E acquires and analyses its transmission spectra. Thanks to an internal broadband light source and beam-shaping optics, the device can reliably measure polymer samples up to 50 μm thick, without any auxiliary optical equipment.

Thanks to the flexible design of the device, it can be easily tailored to operate in different wavelength ranges and with different resolutions, extending the scope of its potential applications.