Refractive index database

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Optical constants of (C3H4O2)n (Polylactic acid, PLA)
Bodurov et al. 2016: PDLA; n 0.405–0.635 µm

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: 24 °C
film_thickness: 45e-6
substrate: glass


PDLA. 45-μm film on glass substrate. 24 °C.


I. Bodurov, I. Vlaeva, A. Viraneva, T. Yovcheva, S. Sainov. Modified design of a laser refractometer, Nanoscience & Nanotechnology 16, 31-33 (2016)


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


Polylactic acid, (C3H4O2)n

Polylactic acid (PLA, (C3H4O2)n) is a biodegradable and bioactive thermoplastic derived from renewable resources like corn starch or sugarcane. It has captured significant attention due to its compostability under industrial conditions, positioning it as an eco-friendly alternative to petroleum-based plastics. PLA is utilized in a multitude of applications ranging from food packaging to biomedicine, such as drug delivery systems and surgical implants. In the realm of optics, PLA is typically transparent, with a refractive index that can be influenced by factors like crystallinity and processing methods. Though its mechanical strength is comparable to that of polystyrene, PLA has a lower melting temperature, which can limit its use in certain high-temperature applications. Nevertheless, due to its biocompatibility and environmentally friendly nature, polylactic acid continues to be a material of interest for both research and commercial purposes.

Other names

  • Poly(lactic acid)
  • Polylactide
  • PLA


  • PLA: Polylactide
  • PDLA: Poly-D-lactide
  • PLLA: Poly-L-lactide
  • PDLLA: Poly-DL-lactide

External links