Decomposition reactions of glycidyl azide polymer (GAP) and poly(glycidyl nitrate) (PGN) have been investigated by pulsed infrared laser pyrolysis and ultraviolet laser photolysis of thin films at 17-77 K. Reactions are monitored by transmission FTIR spectroscopy. Photolysis of GAP at 266 nm shows that the initial reaction steps are elimination of molecular nitrogen with subsequent formation of imines. Warming leads to loss of the imines, most likely as a result of secondary polymerization reactions. Thermal decomposition of GAP by infrared laser pyrolysis reveals products similar to the UV experiments after warming. Laser pyrolysis of PGN indicated that the main steps of decomposition are elimination of NO2 and CH(2)Q from the nitrate ester functional group, followed by rearrangement of the polymer backbone to form carbonyl functional groups. Higher order reactions form numerous small molecule products including NO, CO, CO2, N2O, H2O, HNCO, HCN, HCNO, HONO, and CH4. UV laser photolysis of PGN shows the major products to be CO, CO2, N2O, and polymeric carbonyls. A mechanism is suggested to account for the difference between products in the UV and infrared laser experiments. Quantum yields for destruction of the azide group in GAP and for destruction of the nitrate ester group in PGN are 8 x 10(-3) and 1 x 10(-3), respectively, for 266 nm excitation.