100 Gb/s NRZ-OOK transmission over 14 km standard single mode fiber in the C-band is demonstrated with a simple intensity modulation and direct detection scheme. The transmission concept utilizes single sideband modulation and comprises a single differential digital-to-analog converter with adjustable phase offset, a new dual electrode plasmonic Mach-Zehnder modulator, a laser at 1537.5 nm, standard single mode fibers, a photodiode, an analog-to-digital converter, and linear offline digital signal processing. The presented SSB concept requires no DSP and complex signaling at the transmitter. The demonstrated SSB transmitter increased the possible transmission distance by a factor of 4.6 compared to a DSB transmitter. We also investigated the equalization requirements. A T/2-spaced feedforward equalizer requires 27 taps to achieve transmission over 10 km with a BER below the HD-FEC limit. In comparison to a DSB transmitter, the SSB transmitter reduced the receiver DSP complexity by a factor of 13.7.
Photonic Networks-on-Chip Employing Multilevel Signaling: A Cross-Layer Comparative Study
Photonic network-on-chip (PNoC) architectures employ photonic links with dense wavelength-division multiplexing (DWDM) to enable high throughput on-chip transfers. Unfortunately, increasing the DWDM degree (i.e., using a larger number of wavelengths) to achieve a higher aggregated data rate in photonic links and, hence, higher throughput in PNoCs, requires sophisticated and costly laser sources along with extra photonic hardware. This extra hardware can introduce undesired noise to the photonic link and increase the bit error rate (BER), power, and area consumption of PNoCs. To mitigate these issues, the use of 4-pulse amplitude modulation (4-PAM) signaling, instead of the conventional on-off keying (OOK) signaling, can halve the wavelength signals utilized in photonic links for achieving the target aggregate data rate while reducing the overhead of crosstalk noise, BER, and photonic hardware. There are various designs of 4-PAM modulators reported in the literature. For example, the signal superposition (SS)–, electrical digital-to-analog converter (EDAC)–, and optical digital-to-analog converter (ODAC)–based designs of 4-PAM modulators have been reported. However, it is yet to be explored how these SS-, EDAC-, and ODAC-based 4-PAM modulators can be utilized to design DWDM-based photonic links and PNoC architectures. In this article, we provide a systematic analysis of the SS, EDAC, and ODAC types of 4-PAM modulators from prior work with regards to their applicability and utilization overheads. We then present a heuristic-based search method to employ these 4-PAM modulators for designing DWDM-based SS, EDAC, and ODAC types of 4-PAM photonic links with two different design goals: (i) to attain the desired BER of 10 -9 at the expense of higher optical power and lower aggregate data rate and (ii) to attain maximum aggregate data rate with the desired BER of 10 -9 at the expense of longer packet transfer latency. We then employ our designed 4-PAM SS–, 4-PAM EDAC–, 4-PAM ODAC–, and conventional OOK modulator–based photonic links to constitute corresponding variants of the well-known CLOS and SWIFT PNoC architectures. We eventually compare our designed SS-, EDAC-, and ODAC-based variants of 4-PAM links and PNoCs with the conventional OOK links and PNoCs in terms of performance and energy efficiency in the presence of inter-channel crosstalk. From our link-level and PNoC-level evaluation, we have observed that the 4-PAM EDAC–based variants of photonic links and PNoCs exhibit better performance and energy efficiency compared with the OOK-, 4-PAM SS–, and 4-PAM ODAC–based links and PNoCs.
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- NSF-PAR ID:
- 10327449
- Date Published:
- Journal Name:
- ACM Journal on Emerging Technologies in Computing Systems
- Volume:
- 18
- Issue:
- 3
- ISSN:
- 1550-4832
- Page Range / eLocation ID:
- 1 to 36
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1145/3487365
