Spatial intensity profiling of elastic and inelastic scattering in isotropic and anisotropic liquids by immersion of a spherical silicon photocell

Appl Opt. 2017 Dec 1;56(34):9384-9389. doi: 10.1364/AO.56.009384.

Abstract

The transverse spatial intensity distribution of elastic and inelastic light scattering in passive and active as well as weak and strong scattering liquid media has been studied by using Sphelar One p-n junction silicon spherical photocells. We immersed a Sphelar One in these scattering solutions and measured the photoconductive response in reverse biased photodiode (PD) configuration. The passive weak scattering medium was pure ethanol (EtOH), whereas the passive strong scattering medium was 5CB nematic liquid crystal (NLC). Solutions of 0.1 mM Rhodamine 640 perchlorate laser dye in EtOH and in 5CB NLC were used as active scattering media. The response of Sphelar One was strongly enhanced in 5CB NLC compared to EtOH, as well as in active solutions compared to passive solutions. The morphology of the Sphelar One is already advantageous over conventional one-sided planar PDs inside liquid solutions. This omnidirectional response of the Sphelar One can further be enhanced by optimizing the properties of the surrounding passive elastic and active inelastic scatterers.