Rearrangeable-Nonblocking Five-Port Silicon Optical Switch for 2-D-Mesh Network on Chip

Abstract

We propose and experimentally demonstrate a five-port silicon optical switch based on the optimized Spanke-Beneš structure for 2-D-mesh network on chip. We optimize it by substituting optical waveguide crossings for 2 × 2 optical switching units. By this approach, the total number of optical switching units is reduced from 10 to 8 compared to a five-port optical switch based on Spanke-Beneš structure. The 2 × 2 optical switching unit is based on balanced Mach-Zehnder interferometers with integrated titanium nitride microheaters on both arms. The average operating power consumption of the whole switch is 215 or 178 mW for the left arm or right arm by using single-arm driving, which will be reduced to 89 mW by using dual-arm driving. The insertion losses (excluding coupling losses) of the five optical links under "all-cross" and "all-bar" states are 3.2-6.0 and 3.3-6.2 dB, respectively, in the wavelength range of 1525-1565 nm. The optical signal-to-noise ratios are larger than 12.2 dB in 1525-1565 nm. 40-Gb/s data transmission experiment is implemented to verify the transmission functionality. The 10-90% rising and 90-10% falling time of the optical switching units in the device by thermal tuning are all ∼17 μs.

HoneyComb ROS: A 6 × 6 Non-Blocking Optical Switch with Optimized Reconfiguration for ONoCs

“…= 720 distinct routing states specify different I/O link configurations, which is much smaller than 32,768 possible switching combinations of HCROS. Therefore, there are repetitive combinations that map to the same I/O link [11]. However, if an OSE is replaced with a waveguide crossing or an OSE is constrained in a through/cross (T C ) state, the optical switch can still route all 720 routing states via rearrangement/adjustment of the switching states of the remaining OSEs exploiting the reconfiguration of 2 × 2 OSEs, hence maintaining the property of rearrangeable non-blocking (RNB) switch [11].…”

“…Therefore, there are repetitive combinations that map to the same I/O link [11]. However, if an OSE is replaced with a waveguide crossing or an OSE is constrained in a through/cross (T C ) state, the optical switch can still route all 720 routing states via rearrangement/adjustment of the switching states of the remaining OSEs exploiting the reconfiguration of 2 × 2 OSEs, hence maintaining the property of rearrangeable non-blocking (RNB) switch [11]. Un-optimized HCROS possess 2 15 = 32,768 switching combinations and hold the non-blocking property, while optimized HCROS has 2 12 = 4096 switching combinations, where rearrangement of 12 OSEs leads to RNB properties of the optical switch.…”

“…We estimated IL for un-optimized and optimized HCROS architectures as worst and optimal cases. First, we calculated total IL of the whole switch by considering OSEs in drop or through states for all 720 I/O links using the following Equation (11).…”

“…Optical switches/routers are one of the important building blocks of optical NoCs (ONoC). In the past few years a lot of research has been carried out in regard to designing power and loss efficient optical switch/router architectures [11][12][13][14][15][16][17][18]. An optical switch/router can be designed using different switching fabrics, e.g., a micro-ring resonator (MR) [19] or a Mach-Zehnder switch (MZ) [20] as the basic switching element.…”

Minimizing the number of wavelengths in a cluster WDM mesh-based ONoC through application-specific mapping

“…In the design of on-chip optical networks, the communication architecture is often structured based on optical circuit switching, which causes a blocking problem when the communication links are occupied by different data flows, leading to lower throughput and higher energy consumption [8,9]. The wavelength division multiplexing (WDM) technology enables optical signals of multiple wavelengths to be transmitted in the same waveguide, which avoids blocking and effectively improves the communication performance [10][11][12]. However, the wavelength is a finite resource.…”