1.25G Dual-Port BiDi cSFP 20km Transceiver TX1550/RX1310: 1.25G-cSFP-20-BD

Our EDGEOPTIC 1.25G-cSFP-20-BD is a multi-vendor compatible dual-port compact SFP optical module engineered to maximize port density in Gigabit Ethernet networks. This cSFP transceiver incorporates two independent BiDi (Bidirectional) channels within a single standard SFP form factor, allowing network engineers to effectively double their connectivity capacity without expanding rack footprint.

The 1.25G-cSFP-20-BD operates with both channels transmitting at 1550nm wavelength and receiving at 1310nm, supporting data rates from 1.063 to 1.25 Gbps per channel. Each channel employs BiDi technology utilizing WDM (Wavelength Division Multiplexing) to deliver full-duplex communication over a single fiber strand per port. This module serves as the complementary pair to the 1.25G-cSFP-20-AD (TX1310/RX1550), and both units are required to establish proper bidirectional optical links.

The transceiver utilizes DFB (Distributed Feedback) laser transmitters combined with PIN photodiode receivers for each channel. DFB lasers provide superior wavelength stability and narrower spectral width compared to FP alternatives, which is particularly beneficial for the 1550nm transmission window. With transmit power ranging from -9 to -3 dBm and receiver sensitivity of -23 dBm, the module delivers a guaranteed 14 dB optical link budget. This supports transmission distances up to 20 kilometers over standard single-mode fiber, ideal for metropolitan access networks and extended campus deployments. Actual achievable distance will vary based on fiber plant conditions, connector quality, and accumulated splice losses.

The 1.25G-cSFP-20-BD features a Double LC/UPC connector interface providing two separate optical ports in the compact housing. The electrical interface adheres to CSFP MSA Option 2 specifications, ensuring seamless integration with compatible host platforms. Our cSFP transceiver can be programmed for interoperability with various equipment vendors supporting this compact form factor.

Digital Diagnostic Monitoring (DDM/DOM) functionality provides comprehensive real-time monitoring of operational parameters including transmitted and received optical power for both channels, module temperature, laser bias current, and supply voltage. These diagnostics enable proactive maintenance and streamlined troubleshooting workflows.

The module operates within standard commercial temperature range of 0 to 70°C, appropriate for controlled environments such as central offices and telecommunications facilities. Power is supplied via a single +3.3V rail.

Standards compliance encompasses IEEE 802.3z for Gigabit Ethernet and IEEE 802.3ah for 1000Base-BX20 applications. The transceiver additionally supports 1G Fiber Channel at 1.0625 Gbps for storage area network implementations. Certifications include CE marking, RoHS compliance, and Class 1 laser safety per FDA and IEC 60825-1 requirements.

Typical applications include fiber-to-the-building access networks, enterprise backbone connections, and telecommunications aggregation where port density and fiber conservation are priorities. The dual-channel architecture combined with BiDi technology significantly reduces both equipment costs and fiber infrastructure requirements.

Because our focus is providing top quality service, we perform rigorous quality verification including optical parameter measurements for both channels, connector cleanliness inspection, and EEPROM memory validation testing.