Numerical Modeling of an Integrating Sphere Radiation Source

Published

August 1, 2002

Author(s)

A Prokhorov, Leonard Hanssen

Abstract

Integrating spheres are often used as calibration sources providing uniform radiance within solid angle and/or uniform irradiance at a distance. The best performance in such a system can be achieved if one is able to evaluate as well as predict important characteristics of the sphere system's output such as the spatial and angular distributions of radiance over the exit port or the distribution of irradiance at the external plane of calibration. We have developed the algorithms and specialized software based on Monte Carlo techniques to solve the problem of radiation transfer inside an integrating sphere containing several point sources and conical annular baffle. The new algorithm employs backward ray tracing coupled with the shadow rays technique. As a timesaving procedure, the axial symmetry of the sphere and the superposition principle areused to substitute the sum of single source radiation fields rotated through a specific angle for the radiation field of the complete multiple source sphere. The random (due to the stochastic character of the Monte Carlo method) component of uncertainty for the radiance or irradiance results is less than 0.1%. The results of numerical experiments are used to establish the performance variation as a function of the reflectance and specularity of the sphere wall, the number of radiation sources, the type of baffle used, and the angular distribution of their radiant intensity.

Proceedings Title

Modeling and Characterization of Light Sources, Technical Conference | | Modeling and Characterization of Light Sources | SPIE

Conference Dates

July 8-9, 2002

Conference Location

Undefined

Conference Title

Proceedings of SPIE--the International Society for Optical Engineering

Pub Type

Conferences

Keywords

effective emissivity, Monte-Cralo method, numerical modeling, reciprocity principle, reflection model

Citation

Prokhorov, A. and Hanssen, L. (2002), Numerical Modeling of an Integrating Sphere Radiation Source, Modeling and Characterization of Light Sources, Technical Conference | | Modeling and Characterization of Light Sources | SPIE, Undefined (Accessed November 8, 2024)