The invention discloses a
zoom optical
system for collecting weak optical signals. The
system consists of thirteen lenses with focal lengths being positive, negative, positive, positive, negative, positive, negative, negative, positive, positive, negative, positive and positive in sequence from an object plane. The
system is mainly used for effectively
coupling a weak optical
signal into an
optical fiber, thereby facilitating
data acquisition of a rear-end CCD. For an actual application scene, the system is designed as a
zoom system, and the
object distance ranges from 50 mm to 200 mm. In order to improve the
optical fiber coupling efficiency, parameters of image points on the axis of the optical system are accurately designed, the root-mean-square
diameter of the image points ranges from100 micrometers to 150 micrometers, and the
divergence angle 2alpha of the image points on the axis is 30.6 degrees. Not only can optical fibers be effectively coupled, but also single-optical-
fiber coupling or multi-optical-
fiber-bundle coupling can be satisfied for different application scenes. The working waveband of the system covers visible light and part of near-
infrared light wavebands, andvarious aberrations are well corrected.