Bifocal optical system for distant object tracking.
A new bifocal optical system used for distant object tracking is proposed. This system combines a birefringent element with a conventional glass lens so that the spot image size and its variation with the axial distance can be controlled according to the requirement of a distant object tracker. The lens design for the tracking application is discussed and an example is given. The new lens system provides a more uniform spot image size and an extended focal depth compared to a conventional lens with one focus.
Liu
Xinping
X
Cai
Xianyang
X
Chang
Shoude
S
Grover
Chander
C