title: Double-wedge-plate interferometer for collimation testing: new configurations.
abstract: Some new configurations of a wedge-plate interferometer are described that use two wedge plates for collimation testing with a built-in reference unlike a single wedge plate for which an external reference is required. Theory and measurement results are presented.
authors.forename: K V
authors.initials: KV
authors.lastname: Sriram
authors.forename: P
authors.initials: P
authors.lastname: Senthilkumaran
authors.forename: M P
authors.initials: MP
authors.lastname: Kothiyal
authors.forename: R S
authors.initials: RS
authors.lastname: Sirohi