Here is a summary for how I verify the codes for TO calculation.
So far, we have been using a set of modified GWINC codes to calculate TO noise, but I have not mentioned how did I make sure that the codes were reliable. So I'll try to explain how I check the codes here.
**==What do we compute?==**
For the TO nosie calculation and the optimization, we are interested in:
- effective dn/dT (TR coefficient) of the coatings
- effective alpha (TE coefficient) of the coatings
- total reflectivity of the coatings (including the phase), and transmissivity
**==Beta calculation check==**
For TR coefficient we can compare GWINC with an analytical result (see Gorodetsky,2008, and Evans 2008) (when # of layers ~ 50 or more), see psl:1181. I tried the solution with nH, 1/4 cap and nL, 1/4 and 1/2 cap. All results agree.
**==Alpha calculation check==**
There is no complication in this calculation. The effective alpha is just the sum of all layers. This calculation is quite straight forward.
**==reflectivity check==**
This was done by reducing the coating layers to one or two layers and comparing with an analytical solution by hand. I checked this and the results agreed.
So I think the calculations for TO noise is valid, the noise estimated from the optimized coatings is done with some error check (previous entry). I think we should be ready to order. |