| abstract |
In a gas sensing system, a light emitter can emit light through a gas sample toward a concave reflective surface. The reflective surface can redirect the emitted light to propagate through the gas sample toward a light sensor. Using, optionally, the Beer-Lambert Law, the system can determine a concentration of the gas material in the gas sample. By selecting a specified shape for the reflective surface, such as a complete or partial ellipsoid, and locating the light emitter and the light sensor in specified locations, such as at one or both foci of the ellipsoid, the gas sensing system can reduce variation in optical path length, from optical path to optical path, in the light that propagates from the light emitter, to the reflective surface, and to the light sensor. Reducing the variation in optical path length can improve an accuracy in determining the concentration of the gas material. |