Adjustable Aspheric Collimators  The design employs a spring-mounted optical lens within the mechanical component, which is used for the collimation of the optical fiber beam and can also be used for spatially coupling light into the fiber. By rotating the outer sleeve of the collimator, the internal optical lens can be translated along the optical axis to adjust the distance between the lens and the fiber end face, resulting in different beam sizes. Once the desired position is achieved, the adjustment can be secured by tightening the knurled lock ring on the casing.There are three focal length options: 4.5 mm, 7.5 mm, and 11 mm, with an alignment error of less than 15 mrad when adjusting.