Silicon photonics
Which is a correct challenge of linear-drive optical transceivers without a DSP?
- AWithout a DSP, module power consumption ends up higher than with DSP-based schemes
- BBecause signal compensation relies on the host SerDes, performance must be guaranteed for the whole system, including the host and board traces
- CWithout a DSP, optical signals cannot be generated, so they cannot replace electrical wiring
Show answer and explanation
Answer: B. Because signal compensation relies on the host SerDes, performance must be guaranteed for the whole system, including the host and board traces
In linear drive, there is no part of the module that re-receives and reshapes the signal, so performance is determined by a single end-to-end channel linking the host SerDes transmit waveform, board trace loss, the driver and modulator, the fiber and the receive-side characteristics. If any part falls short, errors increase across the whole link, and verifying interoperability when combining products from different vendors also becomes harder. Also, because the signal cannot be reshaped inside the module, reach is mainly limited to relatively short distances within data centers. Power consumption and latency are lower than with DSP-based schemes.