LCG-Spectro - MULTICHANNEL SPECTROMETER HAVING A SENSITIVE LAYER WITH A LATERAL COMPOSITION GRADIENT

BACKGROUND

Spectrometers without dispersing elements have been developed to reduce their size and weight. These spectrometers comprise a matrix of photodetectors, above which is disposed a set of filters. Each photodetector is equipped with a filter to capture only a portion of the spectrum. Filters have different cutoff frequencies, so that the photodetector can detect different spectral bands. Each filter has a special geometry, and requires a large number of technological steps. Spectrometers with filters therefore have a high manufacturing cost. The technology developed is a compact, weighted and low cost spectrometer.

HOW IT WORKS

The photodetectors belonging to the same column have spectral responses shifted in wavelength by the fact that the composition of the semiconductor alloy forming the photodetectors varies from one pixel to another. With this non-uniform photodetector column, one manages to measure different spectral components of the incident electromagnetic radiation without using filters. Direct bandgaps semiconductor such as InGaN are directly deposited on the matrix.

BENEFITS

• Simplified and less expensive spectrometer
• Not sensitive to vibrations and temperature
• Does not require recalibration
• Compact system
  

DEVELOPMENT STATUS

•Numerical simulation
•Prototype under construction

APPLICATIONS

•Infrared spectroscopy
•Thermography
•Chemical analysis