The multiplexer has the role of routing light from multiple lasers to a single waveguide (WG) on a photonic integrated chip (PIC). The PIC output can be then free-space coupled with a lens to achieve a collimated beam.
The working principle is based on the variation of the optical path through the thermo-optic effect by using heaters for each component to select, by optical interference, the correct path from the PIC input to the common routing WG. The laser-to-PIC coupling is done using a spot-size converter. In the proposed configurations, the multiplexer is composed of switches which are implemented as Mach-Zehnder interferometers (MZIs) or as ring resonators (RRs).
For deployment in applications requiring multi-wavelength laser sources with arbitrary wavelengths.
- Architectures: MZI-based or RR-based switches.
- Compatible with free-space coupled light sources with modal area ~ 8 µm2 (4.7 x 1.7 µm2) near 3.4 µm
- Wavelength tuning: 5 nm (RR-based) or >>10 nm (MZI-based)
- Improving insertion loss performance