1.25G Dual-Port BiDi cSFP 40km Transceiver TX1310/RX1490: 1.25G-cSFP-41-AD

Our EDGEOPTIC 1.25G-cSFP-41-AD is a multi-vendor compatible dual-port compact SFP optical module designed for extended-reach Gigabit Ethernet networks utilizing the 1310/1490nm wavelength scheme. This cSFP transceiver integrates two independent BiDi (Bidirectional) channels within a single standard SFP footprint, enabling network engineers to maximize port density while achieving 40km transmission distance with wavelength allocation flexibility.

The 1.25G-cSFP-41-AD operates with both channels transmitting at 1310nm wavelength and receiving at 1490nm, supporting data rates from 1.063 to 1.25 Gbps per channel. Each channel leverages BiDi technology through WDM (Wavelength Division Multiplexing) for full-duplex communication over individual fiber strands. This module requires its complementary counterpart, the 1.25G-cSFP-41-BD (TX1490/RX1310), to complete bidirectional optical links. The 1310/1490nm wavelength combination provides an alternative to the 1310/1550nm scheme, offering compatibility with network architectures incorporating PON coexistence requirements or specific wavelength planning strategies.

The 40km reach capability addresses metropolitan-scale network deployments where extended transmission distance is essential. Service provider access aggregation, regional enterprise interconnects, and carrier-grade ring architectures benefit from this combination of distance, port density, and wavelength flexibility. The enhanced reach is achieved through optimized optical specifications, with transmit power ranging from -5 to 0 dBm and receiver sensitivity of -24 dBm, delivering a guaranteed 19 dB optical link budget.

The transceiver employs DFB (Distributed Feedback) laser transmitters combined with PIN photodiode receivers for each channel. DFB technology provides the wavelength stability and narrow spectral characteristics required for reliable extended-reach 1310nm transmission. Operating in the 1310nm window where chromatic dispersion is minimal in standard single-mode fiber, the module tolerates 300-400 ps/nm dispersion, well suited for 40km spans. The receiver operates within a focused 20nm bandwidth window (1480-1500nm), optimized specifically for 1490nm wavelength reception. As always, actual achievable distance depends on fiber plant quality, connector losses, and cumulative splice attenuation.

The 1.25G-cSFP-41-AD features a Double LC/UPC connector interface providing two separate optical ports within the compact housing. The electrical interface conforms to CSFP MSA Option 2 specifications, ensuring compatibility with host systems designed for compact SFP modules across multiple vendor platforms.

Digital Diagnostic Monitoring (DDM/DOM) is fully supported, enabling real-time access to critical parameters including transmitted and received optical power for both channels, module temperature, laser bias current, and supply voltage. Comprehensive diagnostics prove particularly valuable for extended-reach deployments where efficient remote troubleshooting minimizes operational overhead.

The module operates within standard commercial temperature range of 0 to 70°C, suitable for controlled environments including central offices, telecommunications facilities, and data centers. A single +3.3V supply provides operating power.

Standards compliance includes IEEE 802.3z for Gigabit Ethernet, IEEE 802.3ah for 1000Base-BX applications, and 1G Fiber Channel at 1.0625 Gbps for storage networking. Regulatory certifications encompass CE marking, RoHS compliance, and Class 1 laser safety per FDA and IEC 60825-1 standards.

Typical deployment scenarios include metropolitan access ring networks, extended campus backbone connectivity, service provider aggregation points, and installations where the 1310/1490nm wavelength plan aligns with existing infrastructure or facilitates overlay network designs alongside PON systems.

Because our focus is providing top quality service, we perform comprehensive quality verification including dual-channel optical parameter measurements, connector cleanliness testing, and EEPROM memory data validation before delivery.