An improved low-optical-power variable focus lens with a large aperture.

Optical Limiting Properties of Colloids Enhanced by Gold Nanoparticles Based on Nonlinear Refraction for Cw Laser Illumination

In this work, thermo-optical properties of gold nanoparticle colloids are studied using continuous wave (CW) laser irradiation at 532 nm. The nanoparticle colloids are fabricated by 18 ns pulsed laser ablation of pure gold plate in the distilled water. The formation of the nanoparticles has been evidenced by optical absorption spectra and transmission electron microscopy. The nonlinear optical ...

Liquid crystal lens focusing in monocentric multiscale imagers

In multiscale imagers a single objective lens is shared by multiple secondary optical systems, so that a high-resolution wide-angle image is acquired in overlapping fields sensed by multiple conventional focal planes. In the “AWARE2” 2 Gigapixel imager, F/2.4 optics cover a 120 degree field of view using a monocentric glass primary lens shared by 221 molded plastic subimagers, each with a 14 Me...

Adaptive liquid lens actuated by liquid crystal pistons.

An adaptive liquid lens actuated by liquid crystal (LC) pistons is demonstrated. It adopts fluid pressure introduced by the reciprocating movement of LC droplets to regulate the liquid-air interface which, in turn, changes the optical power of the resultant liquid lens. The competitive features are compact size, simple fabrication, good optical performance, reasonably fast response time and low...

Variable-focus lens with 30mm optical aperture based on liquid–membrane–liquid structure

Improving the directivity of the plasmonic sectoral horn nanoantenna using lens in its aperture

Horn antennas can result in good impedance matching between the waveguide and free space due to the gradual increase in the aperture size. In this paper, a novel plasmonic sectoral horn nanoantenna based on using lens in the aperture is proposed. It is investigated that in addition to improvement of the directivity, the reflection coefficient is also reduced using the proper lens structure. The...