Chen Sihai

Fabrication, Testing and Integration Technologies of Polymer Microlens for Pt/Si Schottky-Barrier Infrared Charge Coupled Device Applications

A novel polymer refractive microlens array has been formed on the surface of 256(V)×290(H) PtSi Schottky-barrier infrared charge coupled device (IRCCD) image sensors to improve the photoresponsivity of the IRCCD. The fabrication process flows of polymer microlens array are described. An effective aperture ratio in excess of 92% of microlens array has been achieved. An experimental facility to evaluate the optical performance of microlens array is introduced. The measurement results show that the microlens array indicates better than 4% non-uniformity of focal length and high optical performance. The application of the microlens array to improve the photosensitivity of infrared CCD is discussed.

Bionic ommatidia based on microlens array

A simple method is reported to manufacture a planar compound eye using a microlens array. The compound eye, inspired by insects, consists of a microlens array and a waveguide coupled with it. A microlens array with lenses of 50 µm in diameter is fabricated by melting AZ1500 photoresist and then transferring it onto SU-8. With the self-focus method applied, a waveguide array is formed, and each is exactly coupled to a lens. The formation of the waveguide is simulated using finite difference time domain (FDTD) arithmetic, resembling the ommatidia produced in our experiment. The ommatidia is also testified to astrict beam, just as the natural compound eyes do.

Research on hybrid device of Si microlens arrays with long focus and IR detector arrays

A new method, named step simulation, is proposed to fabricate refractive 128/spl times/128 element Si microlens (MLS) arrays for hybrid integration with PtSi IR Focal Plane Arrays (FPAs). By the method, the focal length of rectangle-based multilevel Si MLS arrays is over 1 millimeter, much longer than typical focal length of MLS array fabricated by conventional binary optics Fresnel technique. Si MLS arrays and IR FPAs are coupled with infrared glue. The IR responsivity of the hybrid device is improved significantly.