Abstract: An auto-focus system employing a tunable liquid crystal lens is provided that collects images at different optical power values as the liquid crystal molecules are excited between a ground state and a maximum optical power state tracking image focus scores. An image is acquired at a desired optical power value less than maximum optical power established with the liquid crystal molecules closer a fully excited state than the maximum optical power state having the same image focus score. This drive signal employed during image acquisition uses more power than was used to achieve the same optical power value during the auto-focus scan, while actively driving the liquid crystal molecules is fast. A pause due to image transfer/processing delays after acquisition is employed to allow slow relaxation of the liquid crystal molecules back to the ground state in preparation for a subsequent focus search.

Abstract: A liquid crystal optical device has a layered structure with split liquid crystal layers having alignment surfaces that define in a liquid crystal material pre-tilt angles of opposite signs. Four liquid crystal layers can provide two directions of linear polarization. In the case of a lens, the device can be a gradient index lens, and the alignment surfaces can have a spatially uniform pre-tilt.

Abstract: A tunable liquid crystal lens employing a dual frequency liquid crystal material exhibiting a dielectric anisotropy about a crossover frequency at room temperature is provided. A tunable liquid crystal lens drive signal having low and high frequency components about the crossover frequency, applies a spatially modulated electric field to the dual frequency liquid crystal layer, wherein the differential root means square amplitude determines the optical power. Changing the differential root means square amplitude provides optical power changes under prevailing excitation conditions providing improvements in optical power change speed. Employing drive signal pulses can impart further optical power change speed improvements. A variety of tunable liquid crystal lens structures employing the proposed solution are described.

Abstract: A tunable liquid crystal optical device defining an optical aperture and having a layered structure. The device includes a film electrode formed on a surface of a first substrate and covered by a second substrate, and a contact structure filling a volume within the layered structure and contacting the film electrode. The contact structure is located outside of the optical aperture and provides an electrical connection surface much larger than a thickness of the film electrode, such that reliable electrical connections may be made to the electrode, particularly in the context of wafer scale manufacturing of such a device.

Abstract: Variable liquid crystal devices for controlling the propagation of light through a liquid crystal layer use a frequency dependent material to dynamically reconfigure effective electrode structures in the device. The frequency of a drive signal that generates an electric field in the device may be varied, and the frequency dependent material has different charge mobilities for the different frequencies. At a low charge mobility, the frequency dependent material has little effect on the existing electrode structures. However, at a high charge mobility, the frequency dependent material appears as an extension of the fixed electrodes, and may be used to change the effective electrode structure and, thereby, the spatial profile of the electric field. This, in turn, changes the optical properties of the liquid crystal, thus allowing the optical device to be frequency controllable.

Abstract: A liquid crystal optical device is provided. The optical device includes a liquid crystal cell controlling optical properties of light passing therethrough and has: a liquid crystal layer, a planar electrode located to one side of said liquid crystal layer; an electric field control structure located to the opposite side of the liquid crystal layer; and a wavefront adjustment structure configured to provide optical phase front adjustment. In some embodiments the wavefront adjustment structure is a conductive floating electrode. In other embodiments the wavefront adjustment structure is a weakly conductive structure having spatially variable sheet resistance. In other embodiments the wavefront adjustment structure a weakly conductive structure having spatially variable sheet resistance having a frequency dependent characteristic.

Abstract: A tunable optical imaging system uses a fixed lens and a tunable liquid crystal lens that is operated only outside of an operational range of high aberration. A voltage range applied to change the optical power of the liquid crystal lens is limited to a continuous tunable range of low aberration. The relative positioning between the lens and a corresponding photodetector, and the relative lens powers of a fixed lens and the tunable lens, may be selected to compensate for any optical power offsets resulting from the limitation of the voltage range of the tunable lens. The lens may be operated in either positive tunability or negative tunability mode.

Abstract: A variable optical device for controlling the propagation of light has a body of liquid crystal optical material with a center and a periphery, a heating system including an electrically controllable heat source and a thermal radiator arranged at the periphery for cooling a portion of the body of material. The heating system is operative to generate a spatially modulated temperature gradient and to provide a desired light propagation behavior.

Abstract: Variable liquid crystal devices for controlling the propagation of light through a liquid crystal layer use a frequency dependent material to dynamically reconfigure effective electrode structures in the device. The frequency of a drive signal that generates an electric field in the device may be varied, and the frequency dependent material has different charge mobilities for the different frequencies. At a low charge mobility, the frequency dependent material has little effect on the existing electrode structures. However, at a high charge mobility, the frequency dependent material appears as an extension of the fixed electrodes, and may be used to change the effective electrode structure and, thereby, the spatial profile of the electric field. This, in turn, changes the optical properties of the liquid crystal, thus allowing the optical device to be frequency controllable.

Abstract: Methods are provided for wafer scale manufacturing camera modules without adjustment components to compensate for assembly errors and optical errors incurred within manufacturing tolerances. Camera modules are assembled in wafer arrays from arrays of image sensors, arrays of lens structures and arrays of optical trim elements. At least one of the arrays is a wafer. Lens structures are configured to provide less optical power than necessary to focus an image at infinity on image sensors without trim elements. A test performed during the wafer scale assembly of camera modules, after at least the sensor array and the lens structure array assembled, determines optical errors by identifying optical distortions and aberrations quantified in terms of optical power, astigmatism, coma, optical axis shift and optical axis reorientation deficiencies. Corresponding trim elements are configured to counteract distortions and aberrations prior to singulating useful camera modules from the array.

Abstract: A tunable-focusing liquid crystal lens (TLCL) cell has a liquid crystal layer arranged within a cell gap defined between substrates, a layer of optically transparent material arranged between the first substrate and the LC layer, and a liquid crystal alignment layer arranged between the optically transparent layer and the LC layer. The alignment layer is provided on a third optically transparent substrate having a non-planar shape for giving a non-planar profile to the LC layer, which substrate is obtained from a flexible sheet initially provided with the alignment layer and then formed into the non-planar shape. The lens further has a first optically transparent electrode provided on the second substrate, a second optically transparent electrode provided on either or both of first and third substrates. The electrodes are arranged to generate an electric field acting on the LC layer to change the focal distance of the LC cell. Methods for fabricating such TLCL cell are also provided.

Abstract: A tunable liquid crystal optical device defining an optical aperture and having a layered structure. The device includes a film electrode formed on a surface of a first substrate and covered by a second substrate, and a contact structure filling a volume within the layered structure and contacting the film electrode. The contact structure is located outside of the optical aperture and provides an electrical connection surface much larger than a thickness of the film electrode, such that reliable electrical connections may be made to the electrode, particularly in the context of wafer scale manufacturing of such a device.

Abstract: A wafer level method of manufacturing a liquid crystal optical device removes the need for a rigid barrier fillet while minimizing any risk of contamination of the liquid crystal. An uncured adhesive may be deposited on a bottom substrate and partially cured to form a liquid crystal barrier. After addition of the liquid crystal and a top substrate, the adhesive is fully cured to bond the substrate layers together. An uncured adhesive may be used together with the partially cured adhesive, and may be deposited separately or filled into an extracellular matrix surrounding a plurality of liquid crystal cells. The adhesive may be cured by a variety of means, including light that may be spatially modulated. One or both of the substrates may be deformed during assembly so as to create a structure with a lensing effect on light passing through the liquid crystal region.

Abstract: A tunable optical imaging system uses a fixed lens and a tunable liquid crystal lens that is operated only outside of an operational range of high aberration. A voltage range applied to change the optical power of the liquid crystal lens is limited to a continuous tunable range of low aberration. The relative positioning between the lens and a corresponding photodetector, and the relative lens powers of a fixed lens and the tunable lens, may be selected to compensate for any optical power offsets resulting from the limitation of the voltage range of the tunable lens. The lens may be operated in either positive tunability or negative tunability mode.

Abstract: Variable liquid crystal devices for controlling the propagation of light through a liquid crystal layer use a frequency dependent material to dynamically reconfigure effective electrode structures in the device. The frequency of a drive signal that generates an electric field in the device may be varied, and the frequency dependent material has different charge mobilities for the different frequencies. At a low charge mobility, the frequency dependent material has little effect on the existing electrode structures. However, at a high charge mobility, the frequency dependent material appears as an extension of the fixed electrodes, and may be used to change the effective electrode structure and, thereby, the spatial profile of the electric field. This, in turn, changes the optical properties of the liquid crystal, thus allowing the optical device to be frequency controllable.

Abstract: A liquid crystal optical device has a layered structure with split liquid crystal layers having alignment surfaces that define in a liquid crystal material pre-tilt angles of opposite signs. Four liquid crystal layers can provide two directions of linear polarization. In the case of a lens, the device can be a gradient index lens, and the alignment surfaces can have a spatially uniform pre-tilt.

Abstract: A tunable-focusing liquid crystal lens (TLCL) cell has a liquid crystal layer arranged within a cell gap defined between substrates, a layer of optically transparent material arranged between the first substrate and the LC layer, and a liquid crystal alignment layer arranged between the optically transparent layer and the LC layer. The alignment layer is provided on a third optically transparent substrate having a non-planar shape for giving a non-planar profile to the LC layer, which substrate is obtained from a flexible sheet initially provided with the alignment layer and then formed into the non-planar shape. The lens further has a first optically transparent electrode provided on the second substrate, a second optically transparent electrode provided on either or both of first and third substrates. The electrodes are arranged to generate an electric field acting on the LC layer to change the focal distance of the LC cell.

Abstract: A tunable optical imaging system uses a fixed lens and a tunable liquid crystal lens that is operated only outside of an operational range of high aberration. A voltage range applied to change the optical power of the liquid crystal lens is limited to a continuous tunable range of low aberration. The relative positioning between the lens and a corresponding photodetector, and the relative lens powers of a fixed lens and the tunable lens, may be selected to compensate for any optical power offsets resulting from the limitation of the voltage range of the tunable lens. The lens may be operated in either positive tunability or negative tunability mode.