Depletion of the vibrational ground state of CH4 in absorption spectroscopy at 3.4â¯Âµm in N2 and air in the 1-100â¯Torr range
Keywords: اشباع نوری; Absorption spectroscopy; Cavity enhanced; Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy; Methane; Depletion; Optical saturation;