Abstract: As a new technology,dual-comb spectroscopy has the advantages of high resolution,high sensitivity,wide spectral coverage and high speed measurement,which has unique advantages and broad development prospects in the field of molecular precision spectral analysis.A high temperature gas measurement scheme based on dual-comb spectrum is proposed.Two combs with small refrequency difference are used to achieve high temperature gas absorption spectrum measurement with high precision through asynchronous sampling,and the spectral temperature inversion algorithm is used to obtain the gas temperature value.In the experiment,a dual-comb system with repetition rate of about 205.315 MHz and 205.365 MHz was used to achieve high precision measurement of the absorption spectrum of CO₂ gas at 1 057 K at a wavelength of 4.2 μm.The results show that,as an active temperature measurement technology,it has the ability of accurate measurement of high temperature gas,and has an important application prospect in the field of high temperature measurement of national defense equipment.

Key words: Optical frequency comb, Dual-comb spectroscopy, High temperature measurement, Boltzmann diagram