Broadband 4 $\times$ 4 Nonblocking Silicon Electrooptic Switches Based on Mach–Zehnder Interferometers

Abstract

We report a broadband 4 Â 4 nonblocking optical switch with Mach-Zehnder interferometers (MZIs) as switch elements on a silicon platform. Silicon resistive heaters are used for phase error correction of MZI arms with total thermooptic power consumption of 33.7 mW. Fast switching is enabled by p-i-n diodes, with average electrooptic tuning power of 14.3 mW for the 24 essential switching states as required for nonblocking routing. The average on-chip insertion loss is 5.8-7.7 dB and crosstalk better than À12 dB at wavelength of 1550 nm. Optical transmission experiments using a highthroughput 50 Gb/s quadrature phase-shift keying (QPSK) optical signal reveal that no significant deterioration is observed on constellation diagrams.

Silicon and hybrid silicon photonic devices for intra-datacenter applications: state of the art and perspectives [Invited]

“…The Beneš topology [15] has been attracting interest recently for use in optical switch fabrics because it is reconfigurable, non-blocking, and requires the minimum number of switch elements in an N-by-N switch system. The Beneš network requires 2 log 2 N − 1 number of stages, with each stage containing N∕2 number of 2 × 2 switches.…”

“…Silicon microring resonators [14,19,20,22] and MZIs [15][16][17][18] are the two basic building blocks that are commonly adopted as switch elements in switch fabrics. Figure 8 schematically illustrates basic structures and typical transmission spectra of microring resonators and MZIs.…”

“…The high refractive index contrast between silicon (3.45) and its native oxide, silica (1.44), enables a tight optical confinement in small waveguides and photonic structures fabricated on silicon chips, most commonly on silicon-on-insulator (SOI) chips. Over the past 15 years or so, founded on the early pioneering work by Soref and colleagues dating back to the 1980s [7][8][9], a myriad of silicon photonic devices have been demonstrated, including WDM filters [10,11], high-speed electro-optical (EO) modulators [12,13], and reconfigurable EO/thermo-optical (TO) switches and routers [14][15][16][17][18][19][20][21][22].…”

$4\times 4$ Silicon Optical Switches Based on Double-Ring-Assisted Mach–Zehnder Interferometers

“…N × N optical switches are usually constructed by 1×2 or 2×2 switch elements with scalable switching architectures, such as Crossbar [4]- [6], Benes [7], [8], Switch-and-Select [9], path-independent insertionloss (PILOSS) [10], [11]. Most of the switch elements are based on Mach-Zehnder interferometers (MZIs) [7]- [14] Manuscript received June 6, 2015; revised July 28, 2015; accepted August 16, 2015 and microring resonators (MRRs) [5], [6], [15]- [17].…”

“…Most of the switch elements are based on Mach-Zehnder interferometers (MZIs) [7]- [14] Manuscript received June 6, 2015; revised July 28, 2015; accepted August 16, 2015 and microring resonators (MRRs) [5], [6], [15]- [17].…”