System for optical detection of parameters

A parameter detection system comprising;

• at least one light source capable of emitting light in a direction of an object or a person, where light emitted by the at least one light source is infrared light in a wavelength region of 780 nm to 1,000 nm;
• at least one image sensor being in a position to receive the light reflected from the object or the person;
• and
• at least one band pass filter comprising a substrate and at least one coating being in a position such that light that is incident upon the at least one image sensor must pass through the at least one band pass filter before being received by the at least one image sensor, the at least one band pass filter having a passband in a wavelength region of 780 nm to 1,000 nm, the substrate being made of glass and having a thickness of 0.01 to 2 mm, the substrate having a temperature dependence of refractive index at a wavelength of 850 nm in a temperature range from −40° C. to 60° C. of not more than 10×10−6/K, and the at least one coating having a thickness of not more than 0.5 mm.