A microcavity built from a silicon-nitride/silica quarter-wave stack with a half-wave…

PHYSICS · Multi-part · Fermi University Physics · Optics & Photonics · Wave propagation and light in media · Interference and diffraction

What an Instrument Can See, Ch Media that are designed: plasmons, metamaterials and photonic crystals

Problem

A microcavity built from a silicon-nitride/silica quarter-wave stack with a half-wave silica defect is designed to resonate near

1550\text{ nm}

. Its measured transmission spectrum shows a peak centred at

1552.4\text{ nm}

with a full width at half maximum of

2.35\text{ nm}

. A one-dimensional characteristic-matrix model of the mirrors predicts a mirror-limited quality factor of

2800

for this number of periods. ((a)) Compute the measured quality factor

Q

from the spectrum. ((b)) State the ratio of the model

Q

to the measured

Q

, and give one physical loss that a one-dimensional model cannot represent that would account for the difference.