Single aspherical lens for LD and fiber coupling

Abstract

The invention provides a single aspherical lens for LD and fiber coupling. The single aspherical lens comprises two aspheric curved surfaces and is characterized in that: an aspheric lens section is fitted into an aspherical expression formed by quadratic terms and high-order terms, z=cr2 / 1+square root(1-(1+k)c2r2) + Sigma <N>(i=1)AiEi(x,y), wherein c is a quadric surface curvature of the aspherical lens, r is a radius, k is a quadric surface constant, and A is a high-order coefficient. An LD light source can accept a maximum divergence angle Theta / / =11 degrees in an optical axis, the perpendicularity of Theta is 25 degrees, a light source main optical axis, a lens center axis and a focal point center are required to be on a same straight line, and an allowable error range is from -0.08mmto 0.08mm. The single aspherical lens for LD and fiber coupling has the advantages that lenses are few, the cost is low, the structure is simple, the installation and debugging are easy, the reflection loss is low, the coupling efficiency is high, and the coupling efficiency reaches 88% after using the lens.

Description

technical field [0001] The present invention relates to an optical element, in particular to a single aspherical lens for LD and fiber coupling. Background technique [0002] At present, there are several devices for coupling LD into optical fiber: [0003] 1. Use two cylindrical mirrors to collimate the light beam emitted by the LD light source, and then use the focusing mirror to focus and couple the collimated light into the optical fiber; [0004] First of all, due to the large number of lenses, there are more reflective surfaces, so the energy of the light reflected by the LD through the reflective surface increases, resulting in a significant decrease in the energy entering the optical fiber through the lens; secondly, it is difficult for the main optical axis of each lens to be on a straight line. The coupling efficiency will be lower; again, the increase in the number of lenses will complicate the structure of the entire system and increase the cost; using the profe...

AI Technical Summary

Problems solved by technology

[0008] The structure of this device is complex, the cost increases, and the loss is large; using the professional optical simulation software zemax, the coupling efficiency of this device is 82.9% under ideal conditions

[0009] In summary, the current LD-fiber coupling device, whether it is multiple lenses or a single rod mirror, has the defects of large loss, increased cost, or low coupling efficiency.

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