Study on the Rotational Spectra of the Weak Band(2,3)in the Comet-tail System(A2Π-X2Σ+)of CO+ Using Velocity-Modulation Laser Spectroscopy

Using differential velocity-modulation spectroscopic technique,the Doppler-limited rotational absorption spectra of the weak band(2,3)in the Comet-tail system(A2Π-X2Σ+) of CO+ were measured.The assignment was made for all the observed spectra.Furthermore the effective molecular constants of the states involved in the transition were obtained,and the constants of the lowerstate v＂=3 were reported for first time as to our knowledge.The absorption sensitivity of the experimental sytem was measured to be 1.56×10-6 under the 1slock-in amplifier integration time.