New concepts are presented to realize a chemical oxygen laser (COL) based on the transition from O 2 ( 1 Δ g ) to O 2 ( 3 Σ g ).The chemical oxygen iodine laser (COIL) utilizes the energy transfer from the chemically generated O 2 ( 1 Δ g ) to iodine I ( 2 P 3/2 ) because the stimulated emission cross section of O 2 ( 1 Δ g ) is too small to give a direct oscillation. But since extractable laser energy has no relation to the stimulated emission cross section, a COL has a potential to produce a high energy laser output if it has a long enough active medium to give a positive gain. The intrinsically long upper-state life time enables the storage of large energy, which has a potential give a giant pulsed laser. Since the previous report elucidated the problems 1) , the proposed concepts are based on the consideration of them. Also a Q switched COL oscillator is simulated with a rate equation. The simulation results show that a giant pulse of ~0.05ms width can be obtained with the extraction efficiency of 10-20%.