FORMING AN OPTICAL SYSTEM

A method of forming an optical system is disclosed. The optical system may include a lens and another optical element. The method may include forming a master tool using a lithographic apparatus, using the master tool to form a substrate comprising a plurality of lenses and associated lens alignment features, dicing the substrate to form individual substrates each having a lens with an integrated lens alignment feature, locating the other optical element in a jig, and placing a lens of the plurality of lenses in the jig such that the integrated alignment feature for said lens rests against surfaces of the jig thereby placing the lens is in a desired position relative to the other optical element.