Test Report of Upgraded Long-Distance Optical Transceiver

Upgraded long-distance optical transceivers now support ultra-wideband transmission over distances exceeding 1,000 km with terabit-per-second data rates, high reliability, and multi-vendor interoperability.

High-Capacity Long-Haul Performance

Recent demonstrations by NTT have shown that upgraded optical transceivers can achieve 160 terabits per second over distances exceeding 1,000 km, sufficient to cover major long-haul routes such as the Tokyo-Nagoya-Osaka corridor. This performance was enabled by exploring the X band in addition to conventional C, L, and U bands, and by using ultra-wideband wavelength-division multiplexing (WDM) with a total bandwidth of 27 THz, more than 6.7 times greater than conventional systems. Advanced PPLN-based wavelength band converters and erbium-doped fiber amplifiers (EDFAs) were used to amplify signals across multiple bands, ensuring low-loss, long-distance transmission .

Reliability and Environmental Testing

Upgraded transceivers undergo rigorous reliability tests to ensure stable operation under extreme conditions. Key tests include:

• Damp Heat Test: Evaluates resistance to moisture and high humidity, ensuring long-term functionality in humid environments.
• Life Tests: Accelerated lifetime simulations predict operational lifespan and durability.
• Live Tests: High-speed digital signals are transmitted to measure bit error rates (BER) under stress, confirming consistent performance.
• Temperature and Power Tolerance: Ensures transceivers maintain wavelength stability and power output across industrial temperature ranges . These tests are critical to prevent data loss, latency, and hardware damage, and to maintain optical signal-to-noise ratio (OSNR) and forward error correction (FEC) performance for reliable long-distance communication .

Interoperability and Multi-Vendor Compatibility

Modern long-distance transceivers are designed for multi-vendor interoperability, following standards such as OpenZR+ and OIF 400ZR, which allow small form-factor modules (QSFP-DD, OSFP) to operate efficiently across different network equipment. Interoperability testing ensures:

• Seamless integration with switches, routers, and optical networks from multiple vendors.
• Consistent performance for regional and long-haul IP-over-DWDM links.
• Reduced risk of single points of failure and improved network resilience .

Key Advantages of Upgraded Transceivers

• Ultra-high data rates: Terabit-per-second transmission for high-capacity networks.
• Long-distance coverage: Reliable operation over distances exceeding 1,000 km.
• Wide wavelength support: S, C, L, U, and X bands for ultra-wideband WDM.
• Energy efficiency: Optimized power consumption for high-speed, long-range operation.
• Signal integrity: Immune to electromagnetic interference, maintaining low BER over long distances .

Conclusion

The upgraded long-distance optical transceivers combine ultra-wideband amplification, advanced wavelength conversion, and rigorous reliability testing to deliver high-speed, long-haul performance. Their multi-vendor interoperability and robust environmental tolerance make them suitable for next-generation core optical networks, supporting the growing demand for high-capacity, energy-efficient data transmission.