Nonimaging optical concentrators have applications spanning from solar concentration to optical wireless, as well as collimation for LEDs. Using femtosecond laser irradiation followed by chemical etching (FLICE), the fabrication of millimeter-length concentrators from fused silica substrates with output diameters on the order of a hundred microns is demonstrated. The design of dielectric total internal reflection concentrators (DTIRC) is discussed, and ray trace simulations are provided that compare linear taper (LT) and CPC theta1-theta2 concentrator designs for two use cases: 1) as the primary concentrator and 2) as a secondary concentrator. When used with a spherical lens, an overall geometric concentration ratio of 1300 with 1.1 degree half acceptance angle can be achieved, per simulations. Compared to a ball lens with diameter around 1.5mm, widely used for coupling, a 3x larger acceptance angle can be achieved with a DTIRC of similar height.
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