Abstract
The refractive indices of eleven kinds of polyimide (PI) films formed on silicon substrates have been measured at three wavelengths (0.633, 1.320, and 1.523 µm) in the transverse electric (TE) and transverse magnetic (TM) polarization modes using the prism-coupling method. The wavelength dependence of average refractive indices was fitted using the simplified Cauchy's formula, and the estimated refractive indices at infinite wavelength (ninf) and the coefficients of wavelength dispersion (D) were determined. The PIs having higher ninf exhibit larger D, and the values of D are linearly proportional to ninf for aromatic PIs, while those of wholly alicyclic PIs are very small and deviate from the linearity. In a similar manner, the in-plane/out-of-plane birefringence (Δn) values of the aromatic PIs having higher refractive indices are large and show significant wavelength dependence, while the values of Δn of alicyclic PIs are negligible. Approximate equations are presented for aromatic PIs to estimate ninf and refractive indices at 1.320 and 1.523 µm from a refractive index at 0.633 µm.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
