When the beam from a semiconductor laser is focused through a lens or conducted through a fiber or similar element, it is important to have a clear understanding of the NFP (Near Field Pattern) of the semiconductor laser.
The NFP of a semiconductor laser is extremely small, with a size on the order of 1 um, so precise measurement requires an expansion optics with a high rate of magnification.
The illustration below shows a system capable of precise measurement of the semiconductor laser NFP, using an optics with an expansion magnification rate of 500 times (the A4859-01 NFP...