Light field

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

Petahertz Spintronics.

Abstract: The enigmatic coupling between electronic and magnetic phenomena was one of the riddles propelling the development of modern electromagnetism. Today, the fully controlled electric field evolution of ultrashort laser pulses permits the direct and ultrafast control of electronic properties of matter and is the cornerstone of light-wave electronics. In sharp contrast, because there is no first order interaction between light and spins, the magnetic properties of matter can only be affected indirectly on the much slower tens-of-femtosecond timescale in a sequence of optical excitation followed by the rearrangement of the spin structure. Here we record an orders of magnitude faster magnetic switching with sub-femtosecond response time by initiating optical excitations with near-single-cycle laser pulses in a ferromagnetic layer stack. The unfolding dynamics are tracked in real-time by a novel attosecond time-resolved magnetic circular dichroism (atto-MCD) detection scheme revealing optically induced spin and orbital momentum transfer (OISTR) in synchrony with light field driven charge relocation. In tandem with ab-initio quantum dynamical modelling, we show how this mechanism provides simultaneous control over electronic and magnetic properties that are at the heart of spintronic functionality. This first incarnation of attomagnetism observes light field coherent control of spin-dynamics in the initial non-dissipative temporal regime and paves the way towards coherent spintronic applications with Petahertz clock rates.

Interactive deformation of light fields

Abstract: We present a software pipeline that enables an animator to deform light fields. The pipeline can be used to deform complex objects, such as furry toys, while maintaining photo-realistic quality. Our pipeline consists of three stages. First, we split the light field into sub-light fields. To facilitate splitting of complex objects, we employ a novel technique based on projected light patterns. Second, we deform each sub-light field. To do this, we provide the animator with controls similar to volumetric free-form deformation. Third, we recombine and render each sub-light field. Our rendering technique properly handles visibility changes due to occlusion among sub-light fields. To ensure consistent illumination of objects after they have been deformed, our light fields are captured with the light source fixed to the camera, rather than being fixed to the object. We demonstrate our deformation pipeline using synthetic and photographically acquired light fields. Potential applications include animation, interior design, and interactive gaming.

Atomic-position resolution by quadrature-field measurement

Abstract: An atom passing through a standing light field imparts a position-dependent phase shift to the field. By making a phase-sensitive measurement of the field, it is possible to resolve the atom's position to much less than the wavelength of the light. The field measurement results in the creation of virtual slits, and diffraction and interference phenomena may be observed. The phase measurements give welcher Weg information and enable ``quantum-eraser'' experiments to be realized.

Systems and methods for correcting user identified artifacts in light field images

Abstract: Systems and methods for correction of user identified artifacts in light field images are disclosed. One embodiment of the invention is a method for correcting artifacts in a light field image rendered from a light field obtained by capturing a set of images from different viewpoints and initial depth estimates for pixels within the light field using a processor configured by an image processing application, where the method includes: receiving a user input indicating the location of an artifact within said light field image; selecting a region of the light field image containing the indicated artifact; generating updated depth estimates for pixels within the selected region; and re-rendering at least a portion of the light field image using the updated depth estimates for the pixels within the selected region.

Invited article: attosecond photonics: synthesis and control of light transients.

Abstract: Ultimate control over light entails the capability of crafting its field waveform. Here, we detail the technological advances that have recently permitted the synthesis of light transients confinable to less than a single oscillation of its carrier wave and the precise attosecond tailoring of their fields. Our work opens the door to light field based control of electrons on the atomic, molecular, and mesoscopic scales.