title: Design of achromatic doublets: evaluation of the double-graph technique.
abstract: An example of doublet design using the double-graph technique as described by Kingslake is given. The potential of the double-graph technique is evaluated by applying it to three different cases of doublet design. The technique in its present form is found to give a solution only in one case. In the other two cases the solution can be obtained only by modifying the technique.
authors.affiliation: Indian Institute of Technology, Instrument Design Development Centre, Hauz Khas, New Delhi-110016, India.
authors.forename: K D
authors.initials: KD
authors.lastname: Sharma
authors.forename: S V
authors.initials: SV
authors.lastname: Gopal