6.4-THz-spacing, 10-channel cyclic arrayed waveguide grating for T- and O-band coarse WDM

Abstract

A 6.4-THz-spaced 10 × 10 cyclic arrayed waveguide grating (AWG) supporting 64 THz of bandwidth of the T-and O-bands is designed and fabricated. Cyclic operation was realized using only one diffraction order by combining an AWG with double the number of output waveguides and an array of 2 × 1 couplers. The maximum passband peak deviation of the AWG is around 32% of its channel spacing. Such AWG would be useful for coarse T-band applications or for waveband routing in a cascaded AWG configuration.

A 40 Gb/s Chip-to-Chip Interconnect for 8-Socket Direct Connectivity Using Integrated Photonics

“…In a practical case, where multiple sockets communicate simultaneously with other sockets, the AWGR channel crosstalk can be a limiting factor affecting the entire system performance. Given that the AWGR device used in our experiments was one of the few AWGR structures reported to operate in O-band [23], [24] and was designed for CWDM operation, making it rather challenging to achieve a low channel crosstalk, the system performance of the proposed AWGR-interconnect when operating in all-to-all communication scenaria could be improved via one of the following two approaches: a) To replace the employed AWGR module by a redesigned DWDM O-band AWGR with low-crosstalk characteristics, taking advantage of the improved crosstalk properties of DWDM structures compared to CWDM design, as this has been confirmed by respective C-band AWGR designs where DWDM layouts report on low-crosstalk values in the range of 16.8-25 dB [25]- [29], b) To enrich the system architecture by retaining the CWDM AWGR and equipping every socket with a set of seven unique wavelengths, while adding a DWDM AWG DEMUX at every AWGR output. In this way, all seven wavelengths reaching the same CWDM AWGR output port from seven different originating sockets can be adjusted to have slightly different wavelength values still residing in the same AWGR pass-band, so that finally the DWDM AWG DEMUX can separate them successfully to the destined sockets without suffering from any crosstalk issues.…”

Silicon circuits for chip‐to‐chip communications in multi‐socket server board interconnects

“…According to [22], an in‐band Xtalk value of ‐34 dB is needed for an 8×8 AWGR structure; however, the reported AWGRs exhibit significantly higher XTalk. To overcome this limitation, we have developed a XTalk‐aware routing scheme towards enabling fully loaded AWGR‐based interconnects even with AWGRs that do not meet the necessary Xtalk value [22], as has been typically the case for the integrated AWGRs reported so far [8,9,15,21]. The proposed XTalk‐aware scheme [23] exploits a number of slightly detuned wavelengths around the nominal AWGR channel central wavelength for each spectral band, considering, however, the maximum possible wavelength utilization factor (i.e.…”

400 Gb/s Silicon Photonic Transmitter and Routing WDM Technologies for Glueless 8-Socket Chip-to-Chip Interconnects

“…In this case, the interference components from the other routing paths cause severe performance degradation on the received data signals at due to beat noise that happens within the bandwidth of the Rx PD bandwidth. As described in [15], an AWGR interconnection requires an AWGR device featuring an IXT value of -34 dB and -36 dB to achieve fully-loaded 8×8 and 16×16 connectivity, however the reported AWGRs exhibit significantly higher XT values [7][8][14] [16], preventing their employment in fully-loaded configurations. To overcome this limitation, we have developed a XT-aware wavelengthselection routing scheme that allows for fully-loaded AWGRbased interconnects even when AWGRs with low IXT characteristics are employed, as this has been typically the case for the integrated AWGRs reported so far.…”