Silicon nitride

Silicon Nitride

LIGENTEC offers its proprietary silicon nitride (Si3N4) platform targeted at photonic applications using integrated photonic chips from visible to mid-IR.

Silicon nitride as a material strikes a balance between silicon and silicon oxide.



The waveguides are built by high quality silicon nitride, cladded in high quality silicon dioxide. Nitride thickness is fixed per batch and ranging from 150-1300nm depending on the application. Such high nitride thickness is enabled by LIGENTEC proprietary process, ensuring exceptional mode confinement, sharp bending radius and reduced device footprint. The high nitride thickness permits anomalous dispersion and a high damage threshold that is very important for LIDAR, quantum and nonlinear optical applications of these integrated devices. 

LIGENTEC process offers a state of the art, cost-effective platform with superior critical dimension and thickness control. The process is accompanied by a validated design library, offering a rapid and low cost prototyping solution. The library developed with VLC Photonics includes integrated components for:

  • – Spot converters
  • – Ultra low loss spirals
  • – MZI, MMI
  • – Ring resonators
  • – Filters
  • – AWG
  • – Heaters
An unique feature of the thick waveguides is their anomalous dispersion and their high damage threshold that is important in a range of nonlinear optical applications, including integrated quantum communication, supercontinuum generation in waveguides from pulsed lasers, femtosecond pulse generation from CW lasers using soliton generation in microresonators. The high power threshold enables applications such as LIDAR to propagate Watts of power in the waveguides. In addition the transparency window in the visible renders silicon nitride planar photonic circuits attractive for microfluidics and bio-sensing applications.

The thick silicon nitride waveguides not only enable high damage threshold and low loss, but also a compact chip design as bending radii are very small. With a mode fully confined in the waveguide bends as small as a few tens of micrometers are possible without significant loss.

LIGENTEC enables with its silicon nitride technology products in different application areas.

Additional modules that can be integrated with our passive components:

  • – Heaters
  • – Local cladding removal
  • – SMF spot size converters
  • – 2 layer SiN connected with optical VIA