A method for fabricating millimeter and sub-millimeter size lenses using a high viscosity curable liquid, such as epoxy. The method comprises dispensing a predetermined volume of the curable liquid onto a substrate. The curable liquid preferably has a viscosity higher than 100 cps. Additionally, to reduce spherical aberration, the curable liquid can be cured upside down to leverage the effects of gravity.

Wafer-level optical elements and the concave spacer-wafer apertures in which they are formed are disclosed. The wafer-level optical elements include a spacer wafer comprising a plurality of apertures. Each aperture has a concave shape in a planar cross-section of the spacer wafer and an overflow region intersecting the planar cross-section. The wafer-level optical elements also include an array of optical elements, each optical element of the array being formed of cured flowable material within a respective one of the plurality of apertures. A portion of the cured flowable material forming each optical element extends into the overflow region of the respective aperture of the plurality of apertures. The spacer wafer includes a plurality of apertures, each of the plurality of apertures having a concave shape in a planar cross-section of the spacer wafer. Each of the plurality of apertures includes an overflow region intersecting the planar cross-section.

Disclosed herein are embodiments of a porous aluminum oxide thin film having a surface RMS roughness value of less than 1 nm. The thin film may also comprise phosphorus. The disclosed thin films may have a refractive index of from 1 to 2, such as from 1 to 1.5. Also disclosed are embodiments of as method for making the disclosed thin films, comprising forming an aqueous solution of the alumina precursor, a surfactant and optionally a phosphorus-containing precursor, and depositing the solution on a substrate.

An optics system includes at least one emitting fiber tip that transmits a divergent beam. The divergent beam includes a global maximum intensify of radiation centered with an output optical axis. The divergent beam includes central beams for collimating and periphery beams for disposing. The periphery beams include parasitic radiation of the divergent beam. The optics system includes at least one collimating lens having an output size, output shape, and output optical axis centered thereto and configured to redirect the central beams to a target and redirect the periphery beams into free-space; and at least one redirecting element positioned in between the at least one emitting fiber tip and the at least one collimating lens. The redirecting element includes a first area having an interior size and interior shape to transmit the central beams, and at least one second area outside of the first area to transmit the periphery beams.