Conventions
In order to ensure implicit and explicit compliance with large parts of the API, the following conventions need to be used unless specified otherwise. Below you can find some essential conventions. For specific components or parts of the code base, refer to the respective documentation if certain guidelines need to be followed.
Failure to comply with the following conventions can lead to spurious effects and silent bugs when using the API of this package!
Global optical axis
Commonly, the z-axis is used as the principal optical axis when defining equations or alignment of optical systems and models. This is not the case for BMO, which uses the global y-axis in positive direction as the "global optical axis" in which effects are described. This is motivated by the plotting axes of Makie, which uses a coordinate system where the x- and y-axis form the horizontal plane and the z-axis is orthogonal (upwards).
For (optical) equations that are depended on a global coordinate system, use a basis where the global y-axis ([0,1,0]) is the optical axis and the x-z-axes form the transverse plane. Global propagation along this axis is defined with a direction vector of [0,1,0].
Right-handedness
All coordinate systems are or must be defined right-handed! All normal vectors are or must be defined right-handed!
Counter-clockwise rotation
All rotations are or must be performed in a counter-clockwise manner for a positive rotation angle $\theta > 0$ and vice-versa! For a definition of rotation matrix order, refer to this article.
Normal vector direction
For a closed volume BMO assumes that the surface normal vector points outside of the volume.