The solution to the electromagnetic scattering of a sphere was published by Gustav Mie more than hundred years ago and is well-known as the Mie theory. In Mie theory, the ratio between the scattered and the incident field coefficients in the spherical basis is expressed in terms of the Mie coefficient. These Mie coefficients depend in an intricate manner on the spheres’ radius and the involved material properties of both the sphere and the ambient. To enable a systematic analysis of the accessible optical properties from spheres, these explicit expressions are not useful because they are too complicated. These Mie coefficients simply contain too many degrees of freedom. For fundamental research, it is of utmost importance to have easy expressions at hand that express all values of Mie coefficients that are accessible in general. The precise geometrical and material properties of a sphere that offer these coefficients can be identified in a secondary step. But if these accessible coefficients depend on the least number of degrees of freedom, they would allow for a systematic analysis of all observable effects using spherical scatterers.
These desired simple expressions have been previously identified only for non-absorbing materials. However, a model for absorbing particles has never been reported. Here, while using the optical theorem we derive the generic equations to express any possible Mie coefficient of an absorbing sphere.
Our model for absorbing particles can facilitate the study of absorbing systems such as perfect absorbers, optical torque calculations, cooling, thermal emitters etc. Using the proposed model, one can systematically analyse through all the possible space and search for specific functionality as it will be demonstrated at selected applications at the talk.