A Silicon Nitride MMI O-Band Power Combiner Based on Slot Waveguide Structures

Optical transceivers that function under a high-speed rate condition are demanded to have more optical power ability to overcome the power losses which is a cause of the need of using a larger RF line connected to the Mach-Zehnder modulator for fulfilling the high-speed condition. The classic solution to this problem is to use a better power laser with a high level of 120 milliwatts. However, this solution can be complicated for a photonic chip circuit due to the high cost and nonlinear effects, which can increase the system noise. Therefore, we propose a better solution to increase the power level using a 4x1 power combiner which is based on multimode interference using a silicon nitride slot waveguide structure. Results show that the combiner can function well over the O-band spectrum with high combiner efficiency of at least 98.1% and after a short light coupling propagation of 28.8 μm. This new study shows how it is possible to obtain a transverse electric mode solution for four Gaussian coherent sources using Si3N4 slot waveguides technology. This new technology can be utilized for combining multiple coherent sources that work with a photonic chip at the O-band range.