Tailoring the optical properties of polyvinyl alcohol-polyvinyl pyrrolidone based polymers

In this work, new polymeric based films are fabricated and optically characterized. The new films include poly(vinyl alcohol), plain and blended with poly(vinyl pyrrolidone), comprising glycerin, and acetic acid,as additives. XRD and FTIR analysis were conducted to give insight into the structure of the films. The reflectance and transmittance for these films are measured in the UV-vis-NIR regions. Using these measurements, the refractive index, the permittivity and many other optical constants are retrieved. The results reveal that the fabricated films possess an extinction coefficient that is almost 3 times less, and a refractive index that is 0.1 higher than plain PVA in the telecommunications wavelength range. Besides, a noticeable increase in the refractive index of the films is achieved, up to 0.35 higher compared with silicon dioxide at the near infrared spectral region. Moreover, when compared to silicon and Germanium, in the ultraviolet and visible spectral region, a substantial reduction of 3 to 4 orders of magnitudes in extinction coefficient is achieved, in the favor of the investigated films. Interestingly, the films also show small dispersion over a wide range of wavelength. Therefore, the newly proposed films can be candidates for optoelectronics, solar cells, and integrated optics applications where high refractive index and low loss are desired for high density of fabrication.