Gravitational microlensing has become a mature technique for discovering small gravitational lenses in the Universe which are otherwise beyond our detection limits. Similarly, plasma can help us explore cosmic lenses. Both pulsar scintillation and extreme scattering events of compact radio sources suggest existence $\sim$ AU scale ionized interstellar medium (IISM), whose astrophysical correspo...

Design of a two-reflection, non-deviating beam total internal reflection quarterwave phase retarder is presented. The device treats the two main drawbacks of the Fresnel rhomb which are the lateral shift of the emergent beam and sensitivity of the retardance value to errors in the external angle of incidence. In addition, it is of compact size and the path length of the beam inside the device i...

This article examines the features of solar energy concentrators. The characteristics currently existing types concentration systems are given: a weak system and high system. Their design shortcomings given. It is noted that Frenel lenses one most widely used concentrators, but their optical efficiency limited by low or temperatures, as change in refractive index deformation lens structure obse...

Ultraviolet light (UV)-curable three dimensional (3D) printing has emerged as a prominent additive manufacturing technology, finding diverse applications in industries such figurine production, artifact restoration, dentistry, jewelry design, and etc. For liquid crystal display (LCD) type UV-curable 3D printers, achieving uniform collimated distribution of the illumination system holds paramoun...

The technical and economic sustainability of photovoltaic (PV) systems is heavily affected by the cost and performances of the adopted PV cells. Solar concentrators represent an effective alternative to reduce the solar cell surface and, at the same time, to increase the global conversion efficiency. Such systems include optic elements to concentrate the solar radiation to a small area where hi...