Fig. 1: Instrument Optical Parameters Schematic.

a is a schematic diagram of the optical part of the instrument. Light from LEDs of varying wavelengths is initially emitted and subsequently coupled into a Y-type fiber following fiber welding. The light exits the Y-type fiber and is directed into a Newtonian reflecting telescope. The light is ultimately channeled into a spectrometer for analysis. In the figure, (A), (B), and (C) illustrate the end face connections between the fiber and its coupling; b1 describes the absorption cross sections of some gases that may be encountered in the detection. b2 shows a spectral representation of the coupling processes for multiple LEDs, with the curves (A), (B), and (C) corresponding to the spectral data from the optical fiber end faces illustrated in (A), (B), and (C) of Fig. 1a.