Light field

About: Light field is a research topic. Over the lifetime, 5357 publications have been published within this topic receiving 87424 citations.

Polarized transfer functions of the ocean surface for above-surface determination of the vector submarine light field.

Abstract: A method is developed to determine the underwater polarized light field from above sea surface observations. A hybrid approach combining vector radiative transfer simulations and the Monte Carlo method is used to determine the transfer functions of polarized light for wind-driven ocean surfaces. Transfer functions for surface-reflected skylight and upward transmission of light through the sea surface are presented for many common viewing and solar geometries for clear-sky conditions. Sensitivity of reflection matrices to environmental conditions is examined and can vary up to 50% due to wind speed, 25% due to atmospheric aerosol load, and 10% due to radiometer field-of-view. Scalar transmission is largely independent of water type and varies a few percent with wind speed, while polarized components can change up to 10% in high winds. Considerations for determining the water-leaving radiance (scalar or vector) are discussed.

Head-mounted light field display

Abstract: A head-mounted light field display device, the device comprising at least one multiplexed light field display module adapted to face an eye of a viewer wearing the device, the multiplexed light field display module comprising a light field view image generator and a waveguide with a set of shutters, the light field view image generator operable to generate, over time, a set of beams of light from a different one of a set of light field view images, the shuttered waveguide operable to transmit the set of beams and to open, over time, a different subset of the set of shutters, the subset corresponding to a position associated with the view image, thereby to emit the set of beams via the subset, thereby to display to the viewer a time-varying optical light field representative of the set of view images.

Interferometry with Photon-Subtracted Thermal Light

Abstract: We propose and implement a quantum procedure for enhancing the sensitivity with which one can determine the phase shift experienced by a weak light beam possessing thermal statistics in passing through an interferometer. Our procedure entails subtracting exactly one (which can be generalized to m) photons from the light field exiting an interferometer containing a phase-shifting element in one of its arms. As a consequence of the process of photon subtraction, and somewhat surprisingly, the mean photon number and signal-to-noise ratio of the resulting light field are thereby increased, leading to enhanced interferometry. This method can be used to increase measurement sensitivity in a variety of practical applications, including that of forming the image of an object illuminated only by weak thermal light.

Long working range light field microscope with fast scanning multifocal liquid crystal microlens array

Abstract: The light field microscope has the potential of recording the 3D information of biological specimens in real time with a conventional light source. To further extend the depth of field to broaden its applications, in this paper, we proposed a multifocal high-resistance liquid crystal microlens array instead of the fixed microlens array. The developed multifocal liquid crystal microlens array can provide high quality point spread function in multiple focal lengths. By adjusting the focal length of the liquid crystal microlens array sequentially, the total working range of the light field microscope can be much extended. Furthermore, in our proposed system, the intermediate image was placed in the virtual image space of the microlens array, where the condition of the lenslets numerical aperture was considerably smaller. Consequently, a thin-cell-gap liquid crystal microlens array with fast response time can be implemented for time-multiplexed scanning.

When is the shape of a scene unique given its light-field: a fundamental theorem of 3D vision?

Abstract: The complete set of measurements that could ever be used by a passive 3D vision algorithm is the plenoptic function or light-field. We give a concise characterization of when the light-field of a Lambertian scene uniquely determines its shape and, conversely, when the shape is inherently ambiguous. In particular, we show that stereo computed from the light-field is ambiguous if and only if the scene is radiating light of a constant intensity (and color, etc.) over an extended region.