We use balanced optical low-coherence interferometry to measure the ultralow light power back-reflected and/or back-scattered by interfaces. Indeed, backscattered from surfaces can be a critical source of noise in interferometric gravitational-wave detectors, such as Laser Interferometer Gravitational-Wave Observatory (LIGO), Virgo, or Space Antenna (LISA), and therefore, it is required charact...

We present a white-light spectral interferometric technique for measuring the absolute spectral optical path difference (OPD) between the beams in a slightly dispersive Michelson interferometer with a thin-film structure as a mirror. We record two spectral interferograms to obtain the spectral interference signal and retrieve from it the spectral phase, which includes the effect of a cube beam ...

Recently we reported on chitosan hydrogel systems having excellent laser damage resistance. The measured laser damage threshold (LDT) was better than BK7 glass and quartz, commonly used inorganic optical materials, and 20 to 35 times higher than commercial PMMA, a popular polymer optical material. In this study, we continue our investigation of the phase transition behavior of water within the ...

We propose and demonstrate novel methods that enable simultaneous measurements of the phase index, the group index, and the geometrical thickness of an optically transparent object by combining optical low-coherence interferometer and confocal optics. The low-coherence interferometer gives information relating the group index with the thickness, while the confocal optics allows access to the ph...

This paper investigates the potential of a new integrated solar concentrated photovoltaic (CPV) system that uses solo point focus Fresnel lens for multiple multi-junction cells (MJSCs). The proposed comprises an FL concentrator as primary optical element, multi-leg homogeniser secondary element (SOE), plano-concave lens, and four MJSCs. A three-dimensional model this was developed using ray tra...

Humidity induced changes in the refractive index and thickness of polyethylene glycol (PEG) thin films are in situ determined by optical waveguide spectroscopy. PEG brushes are covalently attached to the surface of a thin gold film on a borosilicate crown glass (BK7) using a grafting-from chemical synthesis technique. The measurements are carried out in an attenuated total internal reflection s...

Discontinuous freeform lens based secondary optics are essential to LED illumination systems. Surface roughness and smooth transition between two discrete sub-surfaces are two of the most common manufacturing defects existing in discontinuous freeform lenses. The effects of these two manufacturing defects on the optical performance of two discontinuous freeform lenses were investigated by compa...

Laser-driven shock experiments were conducted at a synchrotron facility to investigate the dynamic response of polyurethane foam. These coupled in situ x-ray imaging radiograph foam deformations and determine propagation velocity stress waves. To increase amplitude duration pressure load generated by laser–matter interaction, front surface target was covered with confining layer (water BK7 glas...