Tunable chromatic dispersion system using a geometric phase lens and refractive lens pair

A tunable chromatic dispersion system implementing a geometric phase lens and refractive lens pair has been developed. The tunable chromatic dispersion is generated by the diffraction of the geometric phase lens and controlled by varying the distance between the geometric phase lens and a refractive lens. Because the polarization characteristics of the geometric phase lens enables its dual modes as a convex or a concave lens, the system can provide a wide range of tunable chromatic dispersion compared to traditional approaches. The system performance is theoretically analyzed, modeled, simulated, and experimentally verified. Chromatic dispersion ranging from -3.8 mm to 4.4 mm was successfully demonstrated. Furthermore, various factors that influence the spectral resolution were investigated for the chromatic confocal sensor application.