Refractive index database

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Optical constants of PLASTICS
PC - Polycarbonate

Wavelength: µm

Complex refractive index (n+ik)[ i ]

n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula [ i ]


Conditions & Spec sheet

n_is_absolute: false
wavelength_is_vacuum: false
temperature: 20 °C


20 °C


N. Sultanova, S. Kasarova and I. Nikolov. Dispersion properties of optical polymers, Acta Physica Polonica A 116, 585-587 (2009)
(fit of the experimental data with the Sellmeier dispersion formula: Mikhail Polyanskiy)


[Expressions for n]   [CSV - comma separated]   [TXT - tab separated]   [Full database record]


Polycarbonate (PC), (C16H14O3)n

Polycarbonate (PC, (C16H14O3)n) is a high-performance thermoplastic polymer characterized by its remarkable transparency, high impact resistance, and stability over a wide temperature range. Derived from phosgene (COCl2) and bisphenol A (or other bisphenols), its backbone incorporates carbonate groups (-O-(C=O)-O-). This structure imparts PC with its unique blend of properties. Notably, polycarbonate sheets are optically clear (with light transmission similar to glass) and are used where transparency is essential, such as in eyewear lenses, optical discs, and automotive headlights. Additionally, its excellent mechanical properties make it suitable for bulletproof windows, safety helmets, and electronic housings. However, while PC exhibits good resistance to UV radiation, it can yellow over time with prolonged exposure. It's also prone to scratching, which is why many commercial PC products, like eyeglasses, often come with an applied anti-scratch coating. In terms of its refractive properties, the inherent clarity and ability to be molded into complex shapes make polycarbonate a sought-after material for optical applications.


  • Lexan
  • Makrolon
  • Makroclear

External links


Plastics offer a lightweight, cost-effective alternative to traditional optical materials like glass and crystal, making them an increasingly popular choice for a variety of optical applications. Common optical plastics include polymethyl methacrylate (PMMA), polycarbonate, and cyclic olefin copolymer (COC), each with its own set of advantages and limitations. For instance, PMMA is known for its excellent light transmittance and ease of fabrication, while polycarbonate provides higher impact resistance. Plastics are widely used in consumer electronics, automotive lighting, and even in some medical devices, where their lightweight nature and moldability offer distinct advantages. They are particularly well-suited for mass production techniques like injection molding, which allows for the creation of complex optical elements at scale. However, plastics generally have lower refractive indices and can exhibit higher levels of optical dispersion compared to glass, which can be a limitation in high-precision applications. They are also more susceptible to environmental factors such as temperature fluctuations and UV degradation, requiring special additives or coatings for long-term stability. Advances in polymer science are leading to new types of optical plastics with improved characteristics, including higher refractive indices and lower levels of dispersion, expanding their range of potential applications. Overall, plastics provide a versatile and economically viable option for many optical systems, and ongoing research promises to further extend their capabilities.

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