Diffractionlimited aspheric collimation lens

A new method of aspheric lens design is introduced. The aspheric lens was designed according to the contribution of the quadric constant and aspheric coefficient in aspheric equation to aberration of optical system, and the design process of aspheric lens was analyzed. The aspheric collimation lens with a focal length of 50 mm was designed for the fiber coupled semiconductor laser with the numerical aperture NA=0.37 and the fibercore diameter Φ=600μm. The evaluation results show that the image quality almost reaches the diffraction limit, wavefront aberration of the collimation optical system is less than 0.3λ. The experiment results indicate that the aspheric collimation system can maximize the laser efficiency and improve the beam collimation. The validity of the design is proved.