Photoexcitation and photodissociation lasers - Part I: Nitric oxide laser emissions resulting from C(2π) → A(2Σ+) and D(2Σ+) → A(2Σ+) transitions

1-μm laser emission was detected when NO or NO
₂
was flash-photolyzed, with or without dilution, in the vacuum UV above 165 nm. The emission was identified as the C(
²
π)→ A(
²
Σ
⁺
) (0,0) and the D(
²
Σ
⁺
) → A(
²
Σ
⁺
) (1,1) band transitions at 1.2237 and 1.1069 μm, respectively. The C → A(1,1l) and D → A(O,O) bands also lased weakly under better cavity conditions. The total intensity of the 1--μm emissions was found to vary linearly with flash energy, indicating that the pumping mechanism involves a one-photon excitation process. The effects of various additives (He, Ar, H
₂
, CO, N
₂
, O
₂
, N
₂
O, CO
₂
, CF
₄
, and SF
₆
) have been studied. When both CO
₂
and an excess amount of He or Ar were added to NO, 10.6-μm CO
₂
-laser emission was observed concurrently with the 1-μm emission. The 10.6--μm emission is attributed to the nearresonant energy transfer process NO* (v) + CO
₂
(000) → NO* (v -1) + CO
₂
(001) where NO* (v) represents the NO molecule in the vth vibrational level of the A, C, or D state. Additional emissions at 2.6072 and 2.6380 μm were also detected; however, their exact origins are not certain at present.