5. (10 points) A CO; laser operating at ho=10.6 um uses the following optical cavity. r=0.98 d = 75 cm r²=0.8 R₁ = 5 m R₂ = 00 a) Use the ABCD law to find an expression and numerical value for the spot size on the spherical mirror. b) Sketch the intensity (dot) pattern of a TEM₁a mode.