Data‑center top‑of‑rack (ToR) switches currently rely on copper back‑plane fabrics that dissipate > 10 W per 100 Gb/s lane. IPZZ‑040’s 7 fJ/bit operation could reduce the power envelope of a 400 Gb/s port to < 0.3 W, translating into multi‑megawatt savings at scale. Moreover, the wavelength‑division multiplexing capability enables a single fiber to replace dozens of copper pairs, simplifying cabling and improving rack density.