LCGT IFO Mirror Size

Optics

Beam Spot Size (1/e^2 radius)

Minimum Mirror Size (diameter)

ITM

3.5cm

19cm

ETM

3.5cm

19cm

BS

3.5cm

7*3*sqrt(2)+2*t/sqrt(2*n^2-1), where t is the thickness and n is the refractive index.
For t=10cm, d=40cm. Probably this value is a bit overkill. See Hiro Yamamoto's Calculation Below.

PR3

3.5cm

19cm

SR3

3.5cm

19cm

PR2

less than 1cm

10cm is enough

SR2

less than 1cm

10cm is enough

PRM

less than 1cm

10cm is enough

SRM

less than 1cm

10cm is enough