Physical optics

About: Physical optics is a research topic. Over the lifetime, 5342 publications have been published within this topic receiving 101388 citations. The topic is also known as: wave optics.

Scattering of a gaussian beam by an impedance half-plane

Abstract: The diffraction of a Gaussian beam by an impedance half-plane is studied through the method of the modified theory of physical optics. An electric line source, which is defined in the complex space, is used to represent the Gaussian beam. The uniform evaluation of the diffraction integral is performed and the scattering patterns of the field are investigated for various numerical parameters of the incident wave.

Scattering by right angle dielectric wedge

Abstract: An asymptotic solution of electromagnetic waves scattered by a right-angled dielectric wedge for plane wave incidence is obtained. Scattered far fields are constructed by waves reflected and refracted from dielectric interfaces (geometric-optical fields) and a cylindrical wave diffracted from the edge. The asymptotic edge diffracted field is obtained by adding a correction to the edge diffraction of physical optics approximation, where the correction field in the far-field zone is calculated by solving a dual series equation amenable to simple numerical calculation. The validity of this result is assured by two limits of relative dielectric constant \varepsilon of the wedge. The total asymptotic field calculated agrees with Rawlins' Neumann series solution for small \varepsilon , and the edge diffraction pattern is shown to approach that of a perfectly conducting wedge for large \varepsilon . Calculated far-field patterns are presented and the accuracy of physical optics approximation is discussed.

Characteristic Analysis of Compact Spectrometer Based on Off-Axis Meta-Lens

Abstract: Ultra-compact spectrometers with high-resolution and/or broadband features have long been pursued for their wide application prospects. The off-axis meta-lens, a new species of planar optical instruments, provides a unique and feasible way to realize these goals. Here we give a detailed investigation of the influences of structural parameters of meta-lens-based spectrometers on the effective spectral range and the spectral resolution using both wave optics and geometrical optics methods. Aimed for different usages, two types of meta-lens based spectrometers are numerically proposed: one is a wideband spectrometer working at 800–1800 nm wavelengths with the spectral resolution of 2–5 nm and the other is a narrowband one working at the 780–920 nm band but with a much higher spectral resolution of 0.15–0.6 nm. The tolerance for fabrication errors is also discussed in the end. These provides a prominent way to design and integrate planar film-based spectrometers for various instrumental applications.

Digitally tailoring arbitrary structured light of generalized ray-wave duality.

Abstract: Structured lights, particularly those with tunable and controllable geometries, are highly topical due to a myriad of their applications from imaging to communications. Ray-wave duality (RWD) is an exotic physical effect in structured light that the behavior of light can be described by both the geometric ray-like trajectory and a coherent wave-packet, thus providing versatile degrees of freedom (DoFs) to tailor more general structures. However, the generation of RWD geometric modes requires a solid-state laser cavity with strict mechanical control to fulfill the ray oscillation condition, which limits the flexiblility of applications. Here we overcome this confinement to generate on-demand RWD geometric modes by digital holographic method in free space without a cavity. We put forward a theory of generalized ray-wave duality, describing all previous geometric modes as well as new classes of RWD geometric modes that cannot be generated from laser cavities, which are verified by our free-of-cavity creation method. Our work not only breaks the conventional cavity limit on RWD but also enriches the family of geometric modes. More importantly, it offers a new way of digitally tailoring RWD geometric modes on-demand, replacing the prior mechanical control, and opening up new possibilities for applications of ray-wave structured light.

Physics-based polarimetric BRDF models

Abstract: Through the use of measurements and analysis we have devised a series of physics-based analytic models for the BRDF that describe the differential polarization of light scattered from a random rough surface. These models incorporate both intrinsic (refractive index) and extrinsic (statistical moments of the surface height variations) properties of the surface as well as wavelength dependence. Detailed surface statistics are acquired with a stylus scanner. Physical optics theory relates these statistics (and thus the complex coherence factor of the fields at the surface) to the far-field intensity of the scattered light. An outcome of these models is the ability to predict the spectrally varying differential polarization of emittance. Excellent agreement between measured and modeled BRDF’s is demonstrated.