| 摘要 |
In accordance with one embodiment of the present invention, a method of characterizing a lens is provided. According to the method, an optical source such as a laser is configured to generate a collimated beam that is focused along an optical axis at a distance f<SUB>ext</SUB>. A test lens is placed along the optical axis, wherein the test lens is characterized by an effective focal length f<SUB>i </SUB>that is substantially independent of incident irradiance. An output beam generated from the focused optical source and the test lens defines an output intensity profile at an observation plane located a distance Z<SUB>0 </SUB>from the focal point of the optical source. The on-axis intensity I of the output intensity profile along the optical axis at the observation plane is monitored as the placement of the test lens along the optical axis is varied. A z-scan signature of the test lens is generated from the monitored intensity I. The z-scan signature is a plot of intensity as a function of Deltaz, where Deltaz represents a distance between a position of the test lens and the focal point f<SUB>0 </SUB>along the optical axis. The effective focal length f<SUB>i </SUB>of the test lens is characterized by determining the slope m<SUB>0 </SUB>of the z-scan signature at Deltaz=0. Additional embodiments are disclosed and claimed.
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