Let consider a dielectric mirror to be employed in a He-Ne laser of 623 nm. This mirror is composed of alternating layers of MgF2 (n = 1.38) and TiO2 (n = 2.41). This material is to be coated on the crown glass substrate (n = 1.50).
i) Which material must be coated on the glass first?
ii) Determine how thick must the MgF2 layer be for the best outcome?
iii) Determine how thick must the TiO2 layer be for the best outcome?