Cavity enhanced absorption spectroscopy for high precision measurement of greenhouse gases

Greenhouse gases (GHGs) emissions from human activities provided the majority contribution towards global warming, which make our world is now warming faster than at any point in recorded history. High precision measurement of GHGs are very important for monitoring or scientific studies. Here, laser absorption spectroscopy, especially, high sensitivity optical cavity enhanced absorption spectroscopy techniques and instruments for measurement of greenhouse gases were developed. High precision of 0.25 ppm and 2ppb was achieved for measurement of CO₂ and CH₄, by employing off-axis integrated cavity output spectroscopy technique. Using multi-pass cell based mid-infrared absorption spectroscopy, a precision of 0.1 ppb was achieved for N₂O measurement. Results of the developed instruments for applications in GHGs measurements will be presented.