Design and Simulation of Mach Zehnder Interferometer Based Directional Coupler for Optical Coherence Tomography

摘要

We have designed a 2 × 2 directional coupler based on Mach-Zehnder configurations using Si_3N_4 waveguides at three different wavelengths used in optical coherence tomography. The couplers are compact in size and have very low loss. The analysis and calculation of reported design is done using eigen mode expansion (EME) method and is broadband over 100 nm bandwidth at three wavelengths i.e. 850 nm, 1000 nm and 1300 nm respectively. The maximum excess loss reported for all three wavelengths is less than 0.22 dB.