Transceiver architecture analysis plan

Compare throughput, electrical power, optical margin, and package constraints at the same link requirements. Use the chip catalog to identify real devices. Keep unknown inputs empty until evidence or an explicit assumption is available. This folder prepares the later sweep; it contains no simulated performance results.

Architecture cases

Treat modulation, electronics, and placement as separate choices. A CPO engine can use different modulators and electronics.

Proposed case	Starting evidence	Status and limits
Coherent IQ transmitter and coherent receiver	Infinera analysis and interactive map	Physical die image and interpreted function map. Preserve each component's source confidence.
IMDD with an EML	Transceiver teardowns	The author identifies EML assemblies. Some module associations and functions remain uncertain.
IMDD with a silicon MZM	Silicon photonics and CPO tutorial	Intel 100G example is the starting device. Its module rate does not specify every die parameter.
IMDD with a silicon MRM or EAM	Same CPO tutorial	Proposed comparison. Vendor comparison slides are leads, rather than measurements on a common test setup.
Coherent lite	Weekly 114	Author commentary and a comparison chart. Resolve the cited implementation and power boundary first.

For each case, vary electronics between DSP processing, linear pluggable optics (LPO), and linear receive optics (LRO), where the interface permits it. Record the functions at each endpoint explicitly; a label alone does not define their allocation. Vary placement between a pluggable module, near packaged optics (NPO), co packaged optics (CPO), and optical I/O chiplets. These are proposed comparisons, not claims that every combination exists in this archive.

IMDD means intensity modulation and direct detection. An EML combines a laser with an electroabsorption modulator. MZM means Mach–Zehnder modulator. MRM means microring modulator. EAM means electroabsorption modulator. IQ means the two quadratures used to encode a complex optical field.

Throughput and lane counting

Calculate each direction separately. Count active spatial paths, wavelengths per path, and independent polarization channels once. Keep electrical interface lanes separate from optical lanes.

For uniform channels, gross bit rate = spatial paths × wavelengths × polarizations × symbol rate × log2(constellation size). For unequal channels, sum their individual rates. PAM4 carries two mapped bits per symbol. IQ does not add a second multiplier when the QAM constellation size already describes the complex symbol.

Set payload rate = gross bit rate × FEC code rate × framing efficiency × other stated efficiencies. FEC is forward error correction. Define each factor so that overhead is counted once. With probabilistic shaping, use the documented information rate and coding model; do not assume that log2(M) is the payload per symbol. Always label gross, net, one direction, and sum of both directions.

The Infinera article reports 1.6 Tb/s, two wavelengths, two polarizations, 64QAM, and 96 GBd. Under simultaneous full constellation operation, these values imply 2.304 Tb/s gross in one direction. The relationship to 1.6 Tb/s remains unresolved. Do not select a FEC rate simply to force agreement. Source

Power and energy boundaries

Record separate electrical power for lasers and laser cooling, modulators and drivers, receiver and TIA, converters, DSP and FEC, SerDes and retimers, tuning and control, and power conversion. Allocate shared power once. Mark a function as included elsewhere when its power is already inside a measured total.

Report energy per delivered bit as included electrical power / matching payload rate. Show four distinct boundaries: PIC, EIC, one module or optical engine, and the complete link with both endpoints. State whether external lasers, the host interface, and cooling are included. A one direction link denominator requires the power assigned to that transmit endpoint and receive endpoint. A sum of both directions denominator requires the corresponding combined power.

Treat power as fixed plus traffic dependent only when evidence supports that model. Laser electrical power requires optical demand, wall plug efficiency, distribution loss, and the shared laser allocation. Keep source output power, launched power, and received power at their defined reference planes.

Feasibility checks and sweep outputs

Before comparing energy, check optical loss, receiver sensitivity, required error rate, FEC target, and margin. Keep average optical power and optical modulation amplitude (OMA) separate. Coherent cases also need local oscillator power, laser linewidth, and phase noise limits. Check channel bandwidth and equalization, modulation swing, extinction ratio, insertion loss, wavelength spacing, temperature control, electrical reach, and package I/O.

Sweep reach, payload rate, lane arrangement, symbol rate, electrical reach, temperature, and stated device options. Report feasible cases, energy and margin ranges, and the inputs that control the ranking. An unknown input produces an unresolved case or an explicitly assumed sensitivity range. It must not silently become zero.

Evidence checks before running

Attach a URL, section or image, units, operating conditions, and evidence class to every input. Retain image OCR as unverified until checked against the image. Separate source labels, author interpretations, manufacturer claims, calculated values, and assumptions. The latest Infinera notes leave the WLL direction and function unresolved; preserve the competing interpretations in the case. Map corrections

Start with case_template.json. Populate independent cases from verified catalog records. Obtain missing operating power, receiver sensitivity, interface limits, and coding details before publishing architecture rankings.