Table 1.

Molecular oxygen optical transitions between the ground state (O₂ X³Σ_g^-) and the first two electronic excited states (O₂ a¹Δ_g) and (O₂ b¹Σ_g⁺). The transitions are listed in order of increasing energy (eV) (decreasing wavelength in nm). Both monomol (M) and dimol (D) transitions are shown. Data based on [35], [99], [100], [101], [102], [103], [104], [107].

Wavelength	Photon energy	Type	Electronic transition
		(M-Monomol;
		D-Dimol)
1270 nm	0.97 eV	M	O2 X3Σg- → O2 a1Δg v = 0
1065 nm	1.16 eV	M	O2 X3Σg- → O2 a1Δg v = 1
920 nm	1.35 eV	M	O2 X3Σg- → O2 a1Δg v = 2
810 nm	1.53 eV	M	O2 X3Σg- → O2 a1Δg v = 3
760 nm	1.63 eV	M	O2 X3Σg- → O2 b1Σg+ v = 0
690 nm	1.80 eV	M	O2 X3Σg- → O2 b1Σg+ v = 1
633 nm	1.96 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 0 - O2 a1Δg v = 0]
627 nma	1.98 eV	M	O2 X3Σg- → O2 b1Σg+ v = 2
580 nma	2.14 eV	M	O2 X3Σg- → O2 b1Σg+ v = 3
577 nm	2.15 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 1 - O2 a1Δg v = 0]
532 nma	2.33 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 2 - O2 a1Δg v = 0]
495 nma	2.50 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 3 - O2 a1Δg v = 0]
477 nma	2.60 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 0 - O2 b1Σg+ v = 0]
446 nma	2.78 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 1 - O2 b1Σg+ v = 0]
420 nma	2.95 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 2 - O2 b1Σg+ v = 0]
395 nma	3.14 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 a1Δg v = 3 - O2 b1Σg+ v = 0]
380 nma	3.26 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 b1Σg+ v = 0 - O2 b1Σg+ v = 0]
360 nma	3.44 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 b1Σg+ v = 1 - O2 b1Σg+ v = 0]
344 nma	3.60 eV	D	[O2 X3Σg- - O2 X3Σg-] → [O2 b1Σg+ v = 2 - O2 b1Σg+ v = 0]

^aTransitions included for completeness but not discussed in depth in the text.