GBC Photonics 100G Optical Modules - Internal Design

Flowchart of 100G Single Rate and Dual Rate Modules:

Both types of modules have the same architecture. The most important blocks are:

Tx CDR & DRV — a transmitter module supporting four input electrical channels, comprising CDR circuits (Clock and Data Recovery) and laser drivers. Elektrische kanalen can operate at 25.78 Gbps (103.125 Gbps total for single rate modules) or support two speeds: 25.78 Gbps and 27.95 Gbps (total 103.125 Gbps or 111.81 Gbps for modules dual rate).

CDR chip a. A l'axis horizontal — temps — il est sur la deviació de la periode de la signal (jitter), et en el axis vertical — la valor de la signal — la CDR a fornecer decodificazione corretto dell'amplitudo di segnaleon which noise can be applied.

In addition, in the transmitter track, it is used Filtri FIR (finite impulse response),. CDR chip works without reference clock signal and decode the phase and frequency from the input signal.

Rx CDR — a modulus de receptor que se manipular cuatro signalos electricais generados por los diodes de receptor con el CDR de segnale receivable. A CDR works similarly to the transmitting track, but different filters are used in the receiver track.

As a fiber optic line has, in simple terms, the characteristics low pass filter, il signale passaggio tramite un traccia come eseguito Filtri CTLE (continuous-time linear equalization) designed to equalize the characteristics of the signal received by the module.

In addition, in the receiver track, it is used DFE filter (decisional feedback equalization), that is, a logical system in the feedback loop of the decoding system of the logical value of the signal, which helps to eliminate decoding errors of this value.

The effect of CDR operation on signal quality is illustrated by the comparison of the eye diagrams below. Correspondingly, with a working CDR and without such a system.

COUGH - a transmiter optical sub-assembly, i.e. a transmitter assembly built on the basis of previously described lasers of the DML type (most often in single rate modules) or EML (most often in dual rate modules). The four electrical signals are converted into four wavelengths: 1295.56 nm, 1300.05 nm, 1304.58 nm and 1309.14 nm, and then multiplexed into a single fiber as a WDM LAN. ‍

ROZE - optical sub-assembly of receiver, i.e. receiver assembly composed of PIN or APD receiving diodes in the case of modules of greater ranges. A. In the case of APD (avalanche photo diode), it is critically important to ensure a sufficiently low input level consistent with the catalog data.

A signal level that is too high can lead to physical damage to the module. Az,. Con i passaggi di fibra più brevi, può anche essere é necessário para usar silencadores compatíveis.

Kontroller — a microprocessor chip managing the operation of the module chips, Memoria EEPROM including module configuration and communication with the host via I2C bus

Where to use single rate and dual rate modules?