The photoabsorption cross sections of NO have been measured in the wavelength range 150~200nm, and the cross sections deviation from Beer-Lambert law due to the insufficient resolution of light source is discussed qualitatively. From the steady state approximation of quenching reactions, the pressure dependence of foreign gas on the ratio of absorption intensity to the fluorescence intensity is derived. Furthermore, the non-Stern-Volmer behaviors of the C2£S(n=0) state of NO were discussed by assuming the non-predissociated (J<9/2) and the predissociated (J>9/2) rotational levels following different quenching mechanisms.

In the absorption spectra, photoabsorption cross sections and oscillator strengths were measured. Quantum defects were calculated to identify the assignments of absorption features. The measured quantities were also compared with previous results. In fluorescence excitation spectra, ultraviolet and visible emissions were observed, and fluorescence cross sections were measured in the excitation region between 140 and 170 nm. The ultraviolet emission is due to the transition B¡¦2£G¡÷X2£S and the visible emission is associated with B¡¦2£G¡÷B2£S and E2£U+¡÷A2£U+ transitions. In the presence of foreign gas, the collisional quenching effect plays an important role on the fluorescence intensity of C(0) and D(0).We measure the quenching half pressure P1/2 of D(0) respectively. The potential well depth of van der Walls molecule NO-M can be derived from the measured quenching half pressure. In contrast to quenching, the fluorescence intensity of C(1), B(9), B(10) and B(11) are enhanced as the pressure of foreign gas is increased. The enchancement of the fluorescence intensity is attributed to the collisional removal of predissociation.

In the fluorescence excitation spectra, fluorescence cross sections can be measured by the normalization of absorption cross section of A(0) or D(0) states. In the presence of foreign gases, the self-quenching rate constants, the half-quenching pressures and the quenching rate constants of D(0) and D(1) states are measured and the results are compared with the previous works. In the additional of foreign gases, the enhancement of global fluorescence of the strong predissociation states of C(1) and B(9) is due to the collision-induced transition. In the case of N2, the enhancement of fluorescence of £^band is owing to the resonance transfer. Finally, the well depth of the van der Walls molecules which are formed by the excited state of NO with quenching gas can be derived from the measured quenching cross sections.