Are there surge interference risks associated with optical ports on data center switches?

Although the optical ports of data center switches transmit signals via fiber optic cables, the metal casing of the SFP cage is connected to the PCB ground. During a lightning strike, the ground potential rise can couple to the internal circuitry through the casing. Risk path: Transient rise in chassis ground potential → SFP cage → Optical module casing capacitance → Internal module circuitry → Motherboard signal lines. Protection solution: The SFP cage pins are isolated from the signal ground using a Gentex SMD1812-091 gas discharge tube (DC breakdown voltage 90V, current carrying capacity 2kA); the I²C management line is clamped in parallel with an NRESDTLC5V0D8B TVS (VRWM=5V, junction capacitance 0.2pF); In actual testing, when a 6kV surge is injected into the chassis ground, the GDT isolation solution reduces the optical module damage rate by 95% compared to the direct connection solution.