Temperature-dependent refractive index and material dispersion of diamond

The refractive index and material dispersion are determined by the resonance and the plasma frequencies, which are the functions of temperature. It is found that the resonance frequency is linearly proportional to the plasma frequency, and the change of refractive index with temperature is related to the heat capacity. Applying the proposed approach, we calculate the temperature-dependent refractive index and material dispersion of diamond. The evaluated thermo-optic coefficient in the low-frequency limit is compared with the reported results. It approaches zero as temperature extends to absolute zero, and its high-temperature limit at elevated temperatures.

Automated summary

The refractive index and material dispersion are influenced by the resonance and plasma frequencies, which are influenced by temperature. The relationship between the resonance frequency and plasma frequency is linear, and the change in refractive index with temperature is related to heat capacity. Using a proposed method, the temperature-dependent refractive index and material dispersion of diamond were calculated, and compared with reported results for the thermo-optic coefficients at low frequencies. The thermo-optic coefficient approaches zero as temperature approaches absolute zero and reaches a limit for high temperatures.