High-resolution imaging and beam steering using 3 microlens arrays (MLA) is demonstrated. Small lateral displacement of one microlens array is sufficient for large angle beam steering. A prescan lens is added to the system to overcome the discrete addressing problem associated with microlens scanning systems. A hybrid method that uses both geometrical ray tracing optimization and physical optic...

The authors present a novel hyperfidelity fabrication method for microlens arrays. The method consists of the steps of a fabrication of a sacrificial master mold of a microlens array in a soft polymer by photolithography and thermal reflow, b conformal duplication of a daughter mold of complementary patterns in a hard material by dispensing an UV-curable material liquid on top of the polymer mo...

This paper describes the design, fabrication, packaging and testing of a microlens integrated in a multi-layered MEMS microspectrometer. The microlens was fabricated using modified PDMS molding to form a suspended lens diaphragm. Gaussian beam propagation model was used to measure the focal length and quantify M(2) value of the microlens. A tunable calibration source was set up to measure the r...

This paper reports an enhancement in fluorescence detection via the formation of fluidic microlens in micro-optical fluidic system (MOFS). The fluidic microlens is formed by three laminar flows in the expansion chamber. By changing the flow rate of each flow, the shape and focal length of the fluidic lens will be changed. Therefore, the fluidic microlens provides a wide range of tunability to e...

This paper reports on the electrowetting behavior of a flexible poly(dimethylsiloxane) (PDMS) microlens array. A Cr and Au double-layered electrode was formed on an array of microlenses with diameters of 10 microm and heights of 13 microm. A deposition of parylene and a coating of Teflon were followed for electrical insulation as well as for enhancement of the hydrophobicity. On the nearly supe...

Electrowetting on dielectric (EWOD) is a promising technology for variable focus liquid microlens. When an electrical field is applied across a liquid droplet and a dielectric layer, the contact angle of the liquid can be tuned with different applied voltages. Therefore, the focal length of a microlens would vary by simply applying an electrical field without any moving mechanical components. I...

We report on the micromachining of silicon microlens structures by use of scanning-probe gray-scale anodic oxidation along with dry anisotropic etching. Convex, concave, and arbitrarily shaped silicon microlenses with diameters as small as 2 microm are demonstrated. We also confirm the high fidelity of pattern transfer between the probe-induced oxides and the etched silicon microlens structures...

An efficient LED lamp that illuminates the street with high quality is presented. The luminaire shows high optical efficiency, high optical utilization factor, low glare, and illuminates the street with high uniformity. The concept is simple but effective: a cluster of LEDs with TIR lenses are put inside a reflective box, which is covered with a microlens sheet; the reflective cavity improves e...

We propose a novel fluidic assembly-based microfabrication approach for obtaining low-cost, high numerical aperture (NA), doublet microlens arrays. The proposed doublet architecture consists of glass microspheres trapped on a predefined array of silicon microholes and covered with a thin polymer layer. An array of ~56 μm in diameter microlenses with a numerical aperture of ~0.495 were fabricate...

Polarization independent liquid crystal (LC) microlens arrays based on controlling the spatial distribution of the Kerr constants of blue phase LC are simulated. Each sub-lens with a parabolic distribution of Kerr constants results in a parabolic phase profile when a homogeneous electric field is applied. We evaluate the phase distribution under different applied voltages, and the focusing prop...