Licensed from the Dow Chemical Company. 

The LIGHTLINK™ product line consists of materials designed and developed for the fabrication of planar polymeric optical interconnects on rigid and flexible substrates. These siloxane-based materials exhibit high optical clarity and excellent resistance to heat and humidity, making them well suited for optical waveguide applications. These materials may also be applicable to other potential applications where superior optical properties and high environmental stability are required.

Product Uses:
  • Multimode waveguides (830-860 nm)
  • Single-mode waveguides (1300-1500 nm, short paths)
  • Board-level optical interconnects
Material Attributes:
  • Processable using conventional manufacturing equipment and methods
  • Photo-definable to 10µm at 1:1 aspect ratio using aqueous developer
  • High transparency in the visible and near infrared
  • Low optical loss of 0.05 dB/cm at 850 nm
  • Low birefringence of <0.0001 at 850 nm
  • Excellent reliability in extreme temperature and high humidity environments
  • High mechanical robustness

Waveguide fabrication process overview

Step 1. Coat and cure LIGHTLINK™ Clad

Step 2. Coat and softbake LIGHTLINK™ Core

Step 3. Expose, post-exposure bake
and develop LIGHTLINK™ Core

Step 4. Coat and cure LIGHTLINK™ Clad

Core structure on Silicon – spin-coating, softbake and mask lithography.
Source: MicroChem

Waveguide structure on FR4 PCB – spin-coating, softbake and mask lithography.
Source: IBM Zurich