AbstractIn this paper, we propose and discuss an array-grating compressor that is used in high power chirped-pulse amplification Nd:glass laser systems. Theoretical models including various angular errors are developed for the optical design of the array-grating compressor. With a criterion that the stretch in the duration of the compressed pulse due to the combining imperfection must be kept below 25%, we carry out the optical design of the array-grating compressor for a 0.5 ps pulse duration and a 1-m laser-beam diameter. The limitations to groove-width difference, parallelism, and planar are also discussed.