CMOS compatible TeO₂—coated Si₃N₄ inverse parabolic rib waveguide for on-chip supercontinuum generation and high resolution OCT

We present the design and theoretical analysis of CMOS compatible Tellurium oxide (TeO₂)-coated- Si₃N₄ inverse parabolic rib waveguide having upper and lower cladding of barium fluoride (BaF₂) for the generation of highly coherent supercontinuum generation having potential applications in the field of non-linear optics. The proposed design is dispersion engineered by tailoring various geometrical parameters and analyzing their effect on the dispersion profile. The proposed design offers a Zero Dispersion Wavelength (ZDW) near 1.7 μm. The design offers a low value of effective mode area 1.65 μm² and correspondingly high value of non-linear coefficient 2475.68 W⁻¹ km⁻¹ at pump wavelength of 2 μm. Our simulation reports a highly coherent supercontinuum broadening from 1–5 μm spanning over 2.32 octaves in only 1 mm long waveguide when pumped with hyperbolic secant pulses having pulse width 45 fs and peak power 6.1 kW. Additionally, operation at 1.3 μm yields a high axial resolution of 1.007 μm, enhancing its potential for optical coherence tomography. The proposed waveguide can help in various applications ranging from non-linear spectroscopy to optical coherence tomography and from medical imaging to high-bit rate telecommunication. Since the proposed design is CMOS compatible, it can be positioned as an excellent platform for low-loss and high performance future photonic integrated circuits.