To our knowledge the concept of an angular conserved grating-pair disp
ersion compensation system is proposed for the first time, and further
more a model of such a system is developed and applied to the study of
two- and three-lens special cases. A set of easy-to-use dispersion co
mpensation formulas based on geometric optics has been derived and con
firmed by our experimental results. Tunability and a compensation rati
o as high as 27,600 have been achieved with two- and three-lens system
s, respectively. (C) 1995 Optical Society of America