High refractive index materials

Photo of the spincoated high refractive index material on glass
Spincoated high refractive index material on glass

We develop high-refractive index materials for optical applications. Most materials are imprintable.
Refractive index of most polymers is around n = 1.5 and materials with a refractive index above n = 1.60 are considered as “high refractive index” materials. Our proprietary materials provide outstanding optical properties including a high index of refraction ranges between n = 1.75 and n = 2.05 (@ 590 nm) and high optical transparency. Our materials can be deposited as films, and most of them can be nanoimprinted with excellent pattern transfer fidelity with a high-resolution. Applications are many including: printable photonic devices, waveguides, photonic crystals, micro lenses, anti-reflective coating and much more.

Unique Features:

  • High Refractive Index
  • High Transparency in the visible to near-IR region
  • High resolution nanoimprinting
  • UV curable organic polymer with the highest refractive index ever reported

Graph showing transmission of high refractive index hybrid materials
Transmission as a function of wavelength of hybrid materials
Refractive index as a function of wavelength of hybrid materials
Dispersion of hybrid materials

Hybrid Inorganic-Organic Material:

MaterialRefractive index (at 590 nm)Transparency (%) (at 400 nm)Maximum crack-free film thickness (nm)PatterningAnealing* Temperature (°C)Shrinkage (after annealing)
CP12.05>90% (150nm thick film)150UV-NIL40080%
CP21.85>90% (500nm thick film)500Reverse NIL18040%

* Requires annealing at this temperature to reach the specified refractive index

  • G. Calafiore, et.al. “Printable photonic crystals with high refractive index for applications in visible light”, Nanotechnology 27, 1153031 (2016)
  • C. Pina-Hernandez, et.al. “Printable planar lightwave circuits with a high refractive index”, Nanotechnology, 25 325302 (2014). (JOURNAL COVER)
  • C. Pina-Hernandez, et.al. “A Route for Fabricating Printable Photonic Devices with Sub-10 nm Resolution”, Nanotechnology, 24, 065301 (2013).

 


Graph showing transmission of organic polymers
Transmission as a function of wavelength of organic polymers
Refractive index as a function of wavelength of organic polymers
Dispersion of organic polymers

Organic Polymers:

MaterialRefractive index (at 590 nm)Transparency (%) (at 400 nm)Maximum crack-free film thickness (nm)PatterningAnealing Temperature (°C)Shrinkage (after annealing)
CP51.80>90% (1um thick film)>10000Thermal NIL (100°C)N/AN/A
CP5-UV1.78>90% (1um thick film)>10000UV-NILN/AN/A
  • C. Pina-Hernandez, et.al. “Nanoimprinted High-Refractive Index Active Photonic Nanostructures Based on Quantum Dots for Visible Light” (under review 2017)
  • A. Koshelev, et.al. “High refractive index Fresnel lens on a fiber fabricated by nanoimprint lithography for immersion applications”, Optics Letters 41 (15), 3423-3426 (2016)

 


High refractive index nanoimprint examples: