We present a model for ${\ensuremath{\chi}}^{(2)}$ waveguides accounting three modes, two of which make an avoided crossing at the second harmonic wavelength. introduce linearly coupled pure modes and adjust coupling to replicate waveguide dispersion near crossing. Analysis nonlinear system reveals continuous wave (CW) solutions across much parameter space prevalence its modulational instabilit...

Compact waveguide crossing is a fundamental component of optoelectronic fusion chip solutions due to its orders-of-magnitude smaller footprint than that conventional photonic integrated circuits. In this paper, we suggest 2 × compact silicon-on-silica waveguides can implement all the Boolean logic functions, including XOR, AND, OR, NOT, NOR, XNOR, and NAND, operated at 1.55 μm. Three input wave...

A novel design technique for low-loss waveguide crossing using the self-imaging properties of multimode interference (MMI) structures is presented. The technique exploits the observation that optical fields with a small 1/e width relative to that of the MMI structure in the image reformed region experience negligible propagation loss even in the absence of lateral guiding mechanism around the r...

Abstract A phenomenon of a solitary narrow high-Q resonance in planar grating waveguide associated with bound state the continuum (BIC) is revealed analytically. BICs appear when dispersion curves leaking even-parity and non-leaking odd-parity infinite-grating eigenmodes intersect. These intersections engender parity symmetry break eigenmode, causing it to decouple from spatial Fourier harmonic...

We investigate both experimentally and theoretically the waveguiding properties of a novel double trench waveguide where a conventional single-mode strip waveguide is embedded in a two dimensional photonic crystal (PhC) slab formed in silicon on insulator (SOI) wafers. We demonstrate that the bandwidth for relatively low-loss (50dB/cm) waveguiding is significantly expanded to 250nm covering alm...

In-plane optical anisotropy plays a critical role in manipulating light wide range of planner photonic devices. In this study, the strong multilayer 2D GeAs is leveraged and utilized to validate technical feasibility on-chip management. A stamped into an ultra-compact silicon waveguide four-way crossing optimized for operation O-optical band. The measured transmission spectra indicated remarkab...