The chromatic dispersion module with large chromatic focal shift

This paper integrates micro-lenses to develop a miniature chromatic dispersion module with 1.89 mm (400-800 nm) chromatic focal shift for the application of the profile and roughness detection of roll to roll process. The dimension of the designed and fabricated lens module is about 6 mm (long) × 2 mm (diameter) which is far smaller to the commercial system with 136 mm (long) × 25.4 mm (diameter). The module includes two lenses and self-alignment lens holder for assembling and alignment. The system design is based on the principle of afocal, transmission, stacked and refractive type lenses. This paper also compares the commercial lenses (3 mm) and self-fabricated micro lenses (2 mm) system for spot size and focal shift length. White light source was used to test the module could have similar spot sizes after light through the 10X/0.25 objective lenses at individual wavelength (500-650 nm). And the polymer convex lenses have 95 % high transparence in 400-800 nm. As a result of its long chromatic dispersion distance, causes the system could linearity operating at the region not to need the mechanical vertical scanning.