Design and Construction of a Device for Measuring Light-Scattering on Anisotropic Materials

TL;DR

This thesis details the design of a device for optical characterization of anisotropic materials, measuring BSDF, transmission, and reflection across angles and spectral range, with data acquisition and visualization.

Contribution

It introduces a novel device for measuring BSDF and related optical properties of anisotropic media, with detailed mechanical, data acquisition, and control system design.

Findings

Device accurately measures BSDF, transmission, and reflection.

Spectral range from 400 nm to 700 nm covered.

Provides a simple model for scattering characteristics.

Abstract

This is my English translation of my diploma thesis of 1990 (in German). A translation seemed a worthwhile venture because this diploma thesis appears to be unknown today even to close collaborators. Yet it introduces some ideas in BSDF measurements that are still relevant in 2021. This text describes the construction of a device for the optical characterisation of scattering, inhomogeneous, anisotropic media. It measures the transmission and reflexion dependent on two outgoing and two incoming angles, integral over a spectral range from 400 nm to 700 nm. The sample size is 40 x 40 x 10 [cm]. Besides transmission and reflexion values, the scattering characteristic BSDF and absorption can also be determined. The description focuses on the mechanical layout, data acquisition and visualisation of the data. The equipment control with a UNIX workstation and VME bus are detailed. The theoretical part of this thesis gives a simple model for the material scattering characteristic BSDF.