Enhanced Four‐Wave Mixing in Silicon Nitride Waveguides Integrated with 2D Layered Graphene Oxide Films

Abstract

superior performance with respect to speed and operation bandwidth than electronic based devices. [3-5] As a fundamental χ (3) process, FWM has found a wide range of applications in wavelength conversion, [6,7] optical frequency comb generation, [8,9] optical sampling, [10,11] quantum entanglement, [12,13] and many others. [14,15] Implementing nonlinear photonic devices in integrated form offers the greatest dividend in terms of compact footprint, high stability, high scalability, and mass-producibility. [1,2,16] Although silicon has been a leading platform for integrated photonic devices for many reasons, [1] including the fact that it leverages the well-developed complementary metal-oxide-semiconductor (CMOS) fabrication technologies, [17] its strong twophoton absorption (TPA) at near-infrared telecommunications wavelengths poses a fundamental limitation for devices operating in this wavelength region. Other CMOS compatible platforms such as silicon nitride (SiN) and doped silica [2,18] have a much lower TPA, although they still suffer from intrinsic limitation arising from a much lower Kerr nonlinearity. The increasing demand for high performing nonlinear integrated photonic devices has motivated the search for highly

Design of SiN waveguides integrated with graphene oxide films for nonlinear optics

“…Note we used the Kerr nonlinearity n 2 (x, y) instead of the more general third-order nonlinearity (χ (3) ) because the FWM frequencies (pump, signal, idler) in our analysis are close enough together (with a pumpsignal wavelength detuning < 40 nm) compared with any dispersion in n 2 [26,48]. The values of n 2 for silica and SiN used in our calculations were 2.60 × 10 -20 m 2 /W [19] and 2.61 × 10 -19 m 2 /W [34], respectively. The layer-dependent n 2 for GO was obtained from our previous experiments [34], which varied from 1.40 × 10 -14 m 2 /W for N = 1 to 1.34 × 10 -14 m 2 /W for N = 10 and were mainly induced by an increase in inhomogeneous defects and imperfect contact with film thickness.…”

“…Previously [34], we experimentally demonstrated an enhancement of up to ~9.1 dB in the FWM conversion efficiency (CE) of SiN waveguides integrated with layered GO films. We obtained extensive measurements of the loss and Kerr nonlinearity (n 2 ) of the GO films that varied with film thickess and optical power.…”

Graphene Oxide for Integrated Photonics and Flat Optics

“…Enhanced FWM in GO‐coated SiN waveguides was subsequently reported. [ 93 ] SiN waveguides with both uniformly coated (20 mm long, 1 and 2 layers) and patterned (1.5 mm long, 5 and 10 layers) GO films were fabricated (Figure 13b‐i). The maximum CE enhancement (≈9.1 dB) was achieved for the waveguide patterned with 5 layers of GO (Figure 13b‐ii), reflecting the trade‐off between CE enhancement and the loss increase in the hybrid waveguides.…”

Spectral Shaping Based via IntegratedCoupled Sagnac Loop Reflectors in a Self-Coupled Nanowire

“…Finally, this work could have applications to nonlinear devices [20][21][22][23][24][25][26][27][28][29][30] as well as to microwave photonic chips and integrated quantum optics [64-] where advanced optical filter shapes are extremely useful.…”