A system is presented. The system includes an absorption cell filled-with a gas-mixture, a mirror-cum-window comprising a first portion that acts as a first mirror and a second portion that acts as a first window, a second mirror, a plurality of radiation sources to generate a plurality of light beams directed into the absorption cell through the first window followed by reflection of the plurality of light beams between the first mirror and the second mirror to irradiate the gas-mixture resulting in generation of a plurality of transmitted light beams passing out of the absorption cell through the second window, a detector that detects at least one characteristic of the plurality of transmitted light beams resulting in generation of one or more response signals, and a processing subsystem that analyzes the gas-mixture at least based on the one or more response signals.