Accurate Determination of the Temperature Dependence of the Refractive Index of 4H-SiC at the Wavelength of 632 nm

The growing interest for the use of 4H-SiC in photonics is triggering more accurate characterizations this semiconductor from optical and opto-electronic point view. In work we report about new measurements run on an undoped substrate, finalized at determining precise dependence its refractive index temperature visible spectrum, precisely wavelength λ=632.8 nm, a range room (RT) to 400K. Measurements are performed by exploiting properties Fabry-Perot cavity interrogated with laser beam. It known that transmitted radiation intensity shows fringes shift index. By monitoring signal, thermo-optic coefficient dn/dT can be determined resolution approaches 10 -6 K -1 .