We consider here the direct effects resulting from absorption of light in the mirrors (either on the reflecting
surface or in the bulk material) and the indirect effects, such as thermal lensing and thermal distortions.
First, we discuss the steady state (the principles are given in [20]), then the quasi-static case (heating from
an initial uniform temperature [21]), and finally the general dynamical case. We consider the case of cavity
mirrors storing large optical power, heated partially by thermalization of light at the coated face. There is
also heating by propagation losses inside the substrate. We assume thermal equilibrium by thermal
radiation; the mirror being suspended by thin wires in a vacuum, there is no convection loss and we neglect
conduction loss. We further assume a small relative excess of temperature, justified by the good
quality of the coatings and of the bulk silica. With these assumptions, the problem becomes
linear and we can treat separately the contribution to heating caused by the coating and the
bulk substrate. We consider a cylindrical mirror of diameter and of thickness
(see
Figure 7
). The coordinates are radial
, azimuthal
and longitudinal
.
http://www.livingreviews.org/lrr-2009-5 | ![]() This work is licensed under a Creative Commons License. Problems/comments to |