Fig. 5: Fabrication steps of graded index glass pyramid concentrator.
From: Immersion graded index optics: theory, design, and prototypes
Glass pyramid fabrication steps, a thin glass slabs of different refractive indices bonded together and the pyramid shape machined in the stack. Seen in the corners is the ‘checkerboard’ pattern, which is an optical illusion due to graded index layers, b aluminium deposited on the sidewalls, c pyramid in optical contact with solar cell absorbs and concentrates most of the incident light and appears dark.
