Astigmatism using laser diode collimation method
A single biconvex microlens is proposed to correct the astigmatism and ellipticity of a laser diode (LD) beam and focus it to a smallest circular spot. In addition to the divergence, such sources may also show astigmatism between two directions. quality of beam collimation = ? Astigmatism of source causes asymmetric & stronger wavefront error. Based on accurate far-field model of high-power laser diode, a design method of binary optical element for laser diode beams, which can correct the astigmatism of the laser beam, has been developed, and the principle and process has been given in detail. Correction of the astigmatism of a diode laser (2) beam is achieved by utilizing the inherent nature of anamorphic optics (8) to produce astigmatism when decollimated light enters the anamorphic optics, in conjunction with a point diffraction interferometer which provides an observable interference.
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