Most diode lasers suffer from astigmatism: x- and y-components of the beam waist are displaced along the axis. In index-guided lasers, displacement is typically 2-8 µm. They must be collimated in most applications. Astigmatism of source causes. Laser diodes have many advantages: they are small and can be directly modulated, and the power requirements are the modest. However, the output directly from the diode is asymmetric. In this example, collimation of an astigmatic laser diode is investigated with both ray tracing and field tracing techniques, and it is compared with a. 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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