N x N x Mλ electro-optical nanobeam wavelength-multiplexed cross-connect switches using push-push addressing

In this theoretical work, we design elemental and higher-order wavelength-division-multiplexed cross-connects (WXCs): nonblocking space-and-wavelength routing switches to be constructed in a monolithic, industry-standard, silicon-on-insulator (SOI) chip operating at a center wavelength of 1550 nm. Each multi-spectral multi-crossbar 2×2 x Mλ "element" of the network switch is an M-fold cascade connection of λ-diverse SOI Mach-Zehnder interferometers (MZIs), each of which utilizes a nanobeam cavity in each MZI arm. Within the element, each MZI has an electro-optically (EO) controlled local PN-junction "depleter" embedded in each cavity. The cavity voltage commands are (0,0) or (V,V) where V is a "small" reverse bias. Each element can be reconfigured in 2 to 5 ps, depending on Q, with few-fJ/bit switching energy. For the M = 3 case, a compact 6-element 4×4×3λ WXC is presented. In addition, compact new designs are given for a 12-element 8×8×3λ WXC and for 16×16×8λ WXCs employing either 56 or 72 elements.