Light field

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

Light-field streaking for FELs

Abstract: Free-electron lasers provide intense femtosecond radiation pulses with wavelengths in the extreme ultraviolet to x-ray range. Due to the stochastic nature of the light generation scheme, based on self-amplified spontaneous emission, the duration and temporal profile fluctuate from shot to shot. The temporal profile can be measured in a single-shot experiment by light-field streaking, where an infrared light field is used to accelerate photoelectrons generated by the x-ray pulse. The photoelectron energy change depends on the phase of the infrared field at the time of ionization. This technique is extensively used in attosecond metrology where near-infrared streaking fields are employed for the temporal characterization of attosecond XUV pulses. Here, it is adapted for the analysis of pulse durations in the femtosecond range by choosing far-infrared (terahertz) streaking fields.

Design of an optical see-through light-field near-eye display using a discrete lenslet array.

Abstract: In this paper, we propose a novel method to construct an optical see-through light-field near-eye display (OST LF-NED) by using a discrete lenslet array (DLA). The DLA is used as a spatial light modulator (SLM) to generate dense light field of three-dimensional (3-D) scenes inside the user’s eyebox of the system and provide correct focus cues to the user. A corresponding light-field image rendering method is also proposed and demonstrated. The light emitted from the real objects passes through the transparent region of the display panel and the planar area of the DLA successively without redirection, so the user can have a clear view of the real scene as well as the virtual information. The stray light that may degrade the image quality has been analyzed in detail. The experimental result shows that the proposed method is capable of obtaining a corrected depth perception of the virtual information in augmented reality (AR) applications.

Holographic waveguide light field displays

Abstract: A light field display, comprises at least one laser emitter, an optical modulator for modulating light from said laser emitter with video information; a beam focus modulator; an array of beam scanning elements; an electrically controllable beam focus modulator; and at least one at least one waveguide comprising at least one transparent substrate, an input grating and an output grating for extracting light from said waveguide; and an eye tracker.

Quantum theory of multiphoton lasers. II. Systems without detailed balance

Abstract: A quantum-mechanical model for a multiphoton laser is proposed by an obvious generalization of the usual one-photon laser model. The authors consider a class of lasers which preserve detailed balance. This condition is ensured by assuming a multiphoton loss mechanism for the laser light of the same order as the multiphoton gain from the stimulated emission process. Solutions for the stationary density operator of the light field are obtained by a straightforward generalization of the techniques of Scully and Lamb. The multiphoton laser around threshold exhibits behaviour analogous to a second-order phase transition. A non-thermal distribution of multiphoton laser light is achieved above threshold.