Dear All,

Your input will be helpful for me over this topic.

I am trying to understand if there is really a relation of direct energy gap with thermo-optic coefficient (TOC) and if this physics is true.

If we consider following material example,

SiO2, its direct Eg=11 eV while low TOC = 1e-5 /C

on other hand, Si has direct Eg = 3.7 eV, TOC = 1.8e-4 /C,

will it be physically (i mean in physics) correct to give this argument?

I look forward to your expert input.

Thank you...