The beam parameters can then be split into two respective parameters: , for the sagittal plane and and for the tangential plane so that the Hermite–Gauss modes can be written asastigmatic.
Remember that these Hermite–Gauss modes form a base system. This means one can use the separation into sagittal and tangential planes even if the actual optical system does not show this special type of symmetry. This separation is very useful in simplifying the mathematics. In the following, the term beam parameter generally refers to a simple case where and but all the results can also be applied directly to a pair of parameters.
This work is licensed under a Creative Commons License.