Low-loss TeO₂-coated Si₃N₄waveguides for application in photonic integrated circuits

Enhanced Nonlinearity and Engineered Anomalous Dispersion in TeO2-coated Si3N4 Waveguides

“…The results show a higher nonlinear parameter compared to that obtained in stoichiometric Si 3 N 4 waveguides. Although the values obtained are lower compared to those obtained in silicon-rich nitrides or SOI [5] our designs offer the distinct advantages of lower linear losses [22], [23] and negligible nonlinear TPA losses in both Si 3 N 4 and TeO 2 . Our expectations are that the presented designs will offer improved performance in nonlinear devices by having higher nonlinear coefficient, lower nonlinear losses, and anomalous GVD which altogether reduce the threshold power and improve the efficiency of nonlinear interactions for applications such as supercontinuum generation and broadband frequency comb generation.…”

“…Relevant to nonlinear optical devices, the TeO 2 coating can provide the additional height necessary to achieve anomalous GVD hence overcoming the need for thicker Si 3 N 4 waveguides. Further insight regarding measurements and calculations of both insertion and propagation losses can be gained by referring to our previous works on waveguide structures of similar design [22], [23]. However, in the referred papers we reported waveguides of lower height than what we are proposing here.…”

“…By varying h TeO 2 from zero, the proposed waveguide can be tuned from single to multi-mode. Such a waveguide can be fabricated by obtaining low thickness Si 3 N 4 waveguides from a standard CMOS foundry and then depositing a TeO 2 coating through a single step back end process [23]. The deposition is carried out using a radio frequency (RF) sputtering process, as described in [23].…”

“…Such a waveguide can be fabricated by obtaining low thickness Si 3 N 4 waveguides from a standard CMOS foundry and then depositing a TeO 2 coating through a single step back end process [23]. The deposition is carried out using a radio frequency (RF) sputtering process, as described in [23]. The process is straightforward, low-cost and yields near stoichiometry TeO 2 layers which insures low propagations losses.…”

Nonlinear silicon photonics on CMOS-compatible tellurium oxide

“…In this work, we demonstrate strong nonlinear effects in TeO 2 utilizing a different waveguide fabrication technique that avoids any etching or implantation and thus reduces the propagation loss significantly while maintaining small mode area, ensuring high optical intensity in the core [43]. We achieve coherent supercontinuum (SC) generation over the entire telecom band in the normal dispersion regime, which is a factor of 10 broader than the previous demonstration over a decade ago [33].…”