Fig 15 - uploaded by Jose Krause Perin
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Block diagram of coherent receiver architectures based on analog signal processing. Acronyms: local oscillator (LO), polarization beam splitter (PBS), polarization beam rotator (PBR), transimpedance amplifier (TIA), automatic gain control (AGC), analog-to-digital converter (ADC), low-pass filter (LPF).
Similar publications
We demonstrate a silicon-based surface-illuminated CMOS-compatible broadband photodiode with ≤30ps FWHM and above 55% EQE at 850nm for up to 50Gb/s by using photon-trapping micro/nano-structures. This is the fastest reported response for a Silicon photodiode.
We demonstrate a silicon-based
surface-illuminated CMOS-compatible
broadband photodiode with ≤30ps
FWHM and above 55% EQE at 850nm
for up to 50Gb/s by using photontrapping
micro/nano-structures. This
is the fastest reported response for a
Silicon photodiode.
Citations
Multi-wavelength analog coherent links using mode-locked laser (MLL) frequency combs as transmitter and local oscillator (LO) sources are proposed. Carrier recovery (CR) in all wavelength channels is achieved using only two optical phase-locked loops (PLLs), while polarization demultiplexing and static phase offset removal are performed using cascaded optical phase shifters. A three-section Fabry-Perot semiconductor laser structure is proposed for the comb sources. Phase-error performance in a 2.6 Tb/s system using 56-Gbaud dual-polarization quadrature phase-shift keying on 13 channels is studied. For optical and microwave beat linewidths of 2 MHz and 1 kHz, respectively, achieving phase-error penalties below 1.5 dB requires PLL delays below 400 ps. A symmetric CR scheme is shown to achieve better phase-error performance than an asymmetric CR scheme. In 13-channel analog coherent links, the MLL comb-based design is projected to consume 38
$\%$
less power than a resonator-enhanced electro-optic comb-based design and 20
$\%$
less power than a design using arrays of single-wavelength lasers as transmitter and LO sources, excluding modulator driver power, which is identical for the three designs.
Upcoming generations of coherent intra/inter data center interconnects currently lack a clear path toward a reduction of cost and power consumption, which are the driving factors for these data links. In this work, the tradeoffs associated with a transition from coherent C-band to O-band silicon photonics are addressed and evaluated. The discussion includes the fundamental components of coherent data links, namely the optical components, fiber link and transceivers. As a major component of these links, a monolithic silicon photonic BiCMOS O-band coherent receiver is evaluated for its potential performance and compared to an analogous C-band device.
The cloud edge data center will enable reliable and low latency options for the network, and the interconnection among these data-centers will demand a scalable low-complexity scheme. An intensity-modulated and directed detected transmission system is an attractive solution, but chromatic dispersion is the main limitation for higher symbol rate systems. To overcome this challenge, we have proposed and experimentally demonstrated a receiver with shared-complexity between optical and digital domains that enables 80 km transmission reach below KP4 FEC limit for a 32 GBd on-off keying signal. The optical stage consists of optical filters that slices the signal into smaller sub-bands and each is detected by a photodetector. A feedforward neural network and reservoir computing are compared to reconstruct the full signal from the slices and mitigate the chromatic dispersion. Both equalizers have shown similar performance with the advantage of the reservoir computing requiring fewer inputs and easier training process. In this work, we have compared the linear and nonlinear activation functions in the feedforward neural network to investigate the gain of using a nonlinear equalizer. The maximum transmission reach is reduced almost to half,
$\approx$
45 km, when using the linear. The performance is also reduced if a reduced number of slices is used in the receiver, as we have demonstrated. In this case, using 2 slices to reduce the complexity of the system, instead of the total 4, we have shown a
$\approx$
55 km transmission reach below KP4 FEC limit. In this work we have also provided a numerical comparison with 4x8 GBd subcarriers system. The results have shown a 40 km increase in transmission reach compared to the proposed optoelectronic system. The trade-off between performance and complexity should be analyzed for each case, as a different hardware is required in each situation.
