We design and demonstrate a passive physical object whose appearance changes to give a discrete encoding of its pose. This object is created with a microlens array that is placed on top of a black and white pattern. When viewed from a particular viewpoint, the lenses appear black or white depending on the part of the pattern that each microlens projects towards that viewpoint. We introduce the ...

We report on the fabrication of 280-nm AlGaN-based deep-ultraviolet light-emitting diodes sUV LEDsd on sapphire substrates with an integrated microlens array. Microlenses with a diameter of 12 mm were fabricated on the sapphire substrate by resist thermal reflow and plasma dry etching. LED devices were flip-chip bonded on high thermal conductive AlN ceramic submounts to improve the thermal diss...

Single-photon avalanche diode (SPAD) detector arrays generally suffer from having a low fill-factor, in which the photo-sensitive area of each pixel is small compared to the overall area of the pixel. This paper describes the integration of different configurations of high efficiency diffractive optical microlens arrays onto a 32 × 32 SPAD array, fabricated using a 0.35 µm CMOS technology proce...

The study and application of microscale lenses and lens arrays have been actively researched in recent years; new approaches in the fabrication of microlenses and microlens arrays have emerged. Also, novel applications of these microlenses and microlens arrays have been demonstrated. In an effort to disseminate the current advances in this specialized field of microlenses and microlens arrays, ...

Microlens technology for solid state image sensor has been studied in the report. Though microlens can increase the effective aperture ratio, a reflection effect induced by the microlenses would increase optical cross talk and noise level. For high quality imaging, a new technology of micro-wedge optical concentrators (jJ.-WOC), is more suitable.

A cost reduced method of producing injection molding tools is reported and demonstrated for the fabrication of optical microlens arrays. A standard computer-numerical-control (CNC) milling machine was used to make a rough mold in steel. Surface treatment of the steel mold by spray coating with photoresist is used to smooth the mold surface providing good optical quality. The tool and process ar...

A polymer-based flat microlens array is demonstrated. Within each pixel of the array, the polymer presents a circular central-symmetric inhomogeneous orientation. Pixel with such a structure behaves a lens-like character. A suitable amount of liquid crystal mixed in the polymer host can improve not only the lens flexibility but also the lens performance. Moreover, the polymer-based microlens ar...

A real-time dynamically tunable-focus microlens array made from a polymer-liquid-crystal (LC) composite is demonstrated. The polymer was first patterned in microlens array cavities by lamination, and the LC-monomer mixture was then injected to the molded polymer cavities and finally stabilized by UV light-induced networks. Using this new fabrication method, we demonstrated a lens with a spheric...

Microlens array homogenizers are an attractive choice in the field of radiometry and photometry to generate highly uniform beams with high efficiency. In the present paper a microlens array homogenizer used to determine the spectral responsivity of large size, partially filtered photometer is presented. The effect of nonuniformity of the field is shown to be smaller than 0.2% in the whole visib...

We propose a new microlens device structure using two polymerstabilized blue phase liquid crystal layers whose Kerr constant is largely different. Such a polarization independent microlens has a simple structure and desired parabolic phase profile. Its applications for 2D/3D switchable displays and other photonic devices are emphasized.