Firstly, a telescope system is made up with a concave lens and a long-focus convex lens, by which the angle of the parallel beam from the collimator can be change.

Then using another convex lens and a micrometer eyepiece the altered parallel rays is focused, and the imaging size of line pair of collimator imaged on the another convex lens is measured.

Collimation orthopedics of the array laser diode light beam is a traditional optical technical problem.