A dielectric mirror consists of quarter-wave pairs of Ta O ( ) and MgF ( ) plus one…

PHYSICS · Subjective · Fermi University Physics · Optics & Photonics · Interference and diffraction · Interference and diffraction

What an Instrument Can See, Ch Multiple beams: the stack as a matrix and the etalon as a filter

Problem

A dielectric mirror consists of

N=6

quarter-wave pairs of Ta

_2

_5

(

n_H=2.10

) and MgF

_2

(

n_L=1.38

) plus one extra top layer of Ta

_2

_5

, giving the sequence air / HLHLHLHLHLHLH / glass (13 layers, starting and ending with H), each layer a quarter-wave thick at

\lambda=600

nm. The stack is on glass (

n_s=1.52

) and illuminated at normal incidence from air (

n_0=1

). Using the closed-form stack admittance recovered from the characteristic-matrix product,

Y=\dfrac{n_H^2}{n_s}\left(\dfrac{n_H}{n_L}\right)^{2N}

, find the power reflectance

R