Abstract: A system may include one or more electronic devices. Fiber bundles may be provided to convey light. A fiber bundle may have a bend along its length. Fibers for the fiber bundle may be formed from polymer cores coated with polymer claddings. The fibers may have end faces coated with antireflection coatings. The antireflection coatings may be formed from amorphous fluoropolymer deposited from solution. The fluoropolymer may be applied to the end faces of the fibers by dipping, spraying, or by dispensing with a needle dispenser or other dispensing tool. An optical component such as a light-emitting device for a communications system, an illumination system, or a sensor system may provide infrared light that is guided through the fiber bundle.

Abstract: An electronic device may be provided with a display. An optical component window may be formed in the inactive area of the display. The optical component window may transmit infrared light from an infrared light source. The infrared light source may include a diffuser to allow the light source to operate in a flood illumination mode and a structured light mode. The diffuser may include liquid crystal material between first and second substrates. A sealant may surround the liquid crystal layer, and one or more spacer walls may be located between the sealant and the liquid crystal layer. An additional spacer wall may be used outside of the sealant to prevent metal from creating an electrical short between electrodes in the diffuser. Conductive material in the sealant may be used to couple a top electrode to a metal pad on a bottom substrate.

Abstract: A hybrid laser modulation and acid etch process for the creation of a patterned substrate. According to some embodiments, a hole is formed in a glass substrate by first modulating a portion of the substrate in the desired shape. A mask is coated on the glass substrate and is patterned to expose the modulated portion. The glass substrate is then acid etched to remove the modulated portion. Once the modulated portion has been etched, the desired shape may be removed from the glass substrate and the mask may be stripped.

Abstract: An electronic device may be provided with a display. An optical component window may be formed in the inactive area of the display. The optical component window may transmit infrared light from an infrared light source. The infrared light source may include a diffuser to allow the light source to operate in a flood illumination mode and a structured light mode. The diffuser may include liquid crystal material between first and second substrates. A sealant may surround the liquid crystal layer, and one or more spacer walls may be located between the sealant and the liquid crystal layer. An additional spacer wall may be used outside of the sealant to prevent metal from creating an electrical short between electrodes in the diffuser. Conductive material in the sealant may be used to couple a top electrode to a metal pad on a bottom substrate.

Abstract: An electronic device may be provided with a display. The display may have a display cover layer. The display may have an active area with pixels and an inactive area with dummy pixels. The dummy pixels may have structures that are optically matched to the pixels so that the dummy pixels and pixels have similar visual appearances when the display is off. An optical window may be formed in the inactive area. A light-based component such as an ambient light sensor, proximity sensor, or image sensor may be mounted in the electronic device in alignment with the optical window. A polarizer layer may overlap the active and inactive areas of the display. An opening in the polarizer or a bleached unpolarized portion of the polarizer may be aligned with the optical window.

Abstract: An electronic device may have a display. The display may be mounted in a housing and may have a window to accommodate a camera or other electrical component. The display may have multiple substrate layers. A hole may be formed in one of the substrate layers to form additional space within the housing to accommodate the electrical component. The hole may be drilled partway through a substrate layer to form an annular thinned region. The annular thinned region may be cracked to release a disk-shaped portion of the substrate layer and form the hole. A ring of sealant may surround the hole to help cushion the display substrate layers during drilling operations. Column spacer structures may be formed on a portion of a display substrate that is overlapped by the hole.

Abstract: Laser lift-off methods are described in which optical flatness is provided on the back side of a temporary substrate using either an optical layer or optical liquid. A laser is directed through the optical layer or optical liquid and a back side of the temporary substrate to decompose a portion of a process layer supported on a front side of the temporary substrate, followed by separation of the process layer and the temporary substrate.

Abstract: A hybrid laser modulation and acid etch process for the creation of a patterned substrate. According to some embodiments, a hole is formed in a glass substrate by first modulating a portion of the substrate in the desired shape. A mask is coated on the glass substrate and is patterned to expose the modulated portion. The glass substrate is then acid etched to remove the modulated portion. Once the modulated portion has been etched, the desired shape may be removed from the glass substrate and the mask may be stripped.

Abstract: An electronic device may have layers of glass for forming components such as a display. A display cover glass layer may overlap an array of pixels. A touch sensor may be formed under the display cover glass layer. Conductive structures such as transparent conductive electrodes or other conductive layers of material may be formed on the outer surface of the display cover glass layer. The electrodes on the outer surface of the display cover glass layer may be coupled to metal contacts and other circuitry on the inner surface of the display cover glass layer using conductive vias. Vias may be provided with barrier layers, opaque coatings, tapers, and other structures and may be formed using techniques that enhance compatibility with chemical strengthening processes.

Abstract: Laser processing techniques may be used to form structures for electronic devices. A laser processing system may be provided with lasers and positioners for moving laser beams across a structure to be processed such as a layer of glass or other material. A laser such as a pulsed infrared laser may be move along a path across the layer of material. The laser may create a series of damaged regions along the path. A portion of the layer may be removed from other portions of the layer by breaking off the portion of the layer along the path. Laser-induced heating techniques and mechanical stress-inducing techniques may be used to impart stress to the layer of material to help break off the portion. The layer may include one or more sublayers such as layers of glass substrate material in a display.

Abstract: An electronic device may have a display. The display may be mounted in a housing and may have a window to accommodate a camera or other electrical component. The display may have multiple substrate layers. A hole may be formed in one of the substrate layers to form additional space within the housing to accommodate the electrical component. The hole may be drilled partway through a substrate layer to form an annular thinned region. The annular thinned region may be cracked to release a disk-shaped portion of the substrate layer and form the hole. A ring of sealant may surround the hole to help cushion the display substrate layers during drilling operations. Column spacer structures may be formed on a portion of a display substrate that is overlapped by the hole.