40GBASE-LR4 CWDM and PSM QSFP+ Transceiver Links

There area unit 40GBASE-SR4 QSFP+ transceivers and 40GBASE-LR4 QSFP+ transceivers. It's well-known that fortyGBASE-SR4 uses a parallel multimode fiber (MMF) link to realize 40 G. It offers four freelance transmit and receive channels, every capable of ten G operation for associate mixture rate of 40G over a hundred meters of OM3 MMF or a hundred and fifty meters of OM4 MMF. whereas for 40GBASE-LR4 QSFP+ transceivers, there area unit 2 styles of links. One is coarse wavelength division multiplexing and also the alternative is parallel single-mode fiber. what is the difference?

40GBASE-LR4 coarse wavelength division multiplexing QSFP+ Transceiver

QSFP-40GE-LR4, one amongst 40GBASE-LR4 coarse wavelength division multiplexing QSFP+ transceivers, is compliant to 40GBASE-LR4 of the IEEE P802.3ba customary. The optical interface could be a duplex LC connection. It will support transmission distance up to ten metric linear unit over single-mode fiber by minimizing the optical dispersion within the long-haul system.

This transceiver converts four inputs channels of ten G electrical knowledge to four coarse wavelength division multiplexing optical signals by a driven 4-wavelength distributed feedback (DFB) optical device array, and so multiplexes them into one channel for forty G optical transmission, propagating out of the transmitter module from the SMF. Reversely, the receiver module accepts the forty G coarse wavelength division multiplexing optical signals input, and demultiplexes it into four individual 10G channels with totally different wavelengths. The central wavelengths of the four coarse wavelength division multiplexing channels area unit 1271, 1291, 1311 and 1331 nm as members of the coarse wavelength division multiplexing wavelength grid outlined in ITU-T G694.2. every wavelength channel is collected by a separate ikon diode and output as electrical knowledge when being amplified by a transimpedance electronic equipment (TIA).

40GBASE-LR4 PSM QSFP+ Transceiver

Different from coarse wavelength division multiplexing QSFP+ transceiver that uses a LC connection, parallel single-mode QSFP+ could be a parallel single-mode optical transceiver with associate MTP/MPO fiber ribbon connection. It offers four freelance transmit and receive channels, every capable of ten G operation for associate mixture rate of forty G over single-mode fiber regarding ten metric linear unit. The cable cannot be twisted to stay correct channel to channel alignment.

In a parallel single-mode QSFP+, the transmitter module accepts electrical input signals and also the receiver module converts parallel optical input signals via a photograph detector array into parallel electrical output signals. The receiver module. All knowledge signals area unit differential and support a knowledge rates up to ten.3 G per channel.

Difference of 2 Links

What's the distinction of those 2 links? From the point of view of optical transceiver module structure, parallel single-mode looks additional price effective as a result of it uses one uncooled CW optical device that splits its output power into four integrated semiconducting material modulators. Besides, its array-fiber coupling to associate MTP connection is comparatively easy. From the point of view of infrastructure, parallel single mode is dearer, as a result of once the link distance is long, parallel singlemode uses eight optical singlemode fibers whereas coarse wavelength division multiplexing uses solely a pair of optical singlemode fibers. For additional regarding their variations, please see the subsequent table:

What's additional, within the knowledge center fiber infrastructure, the patch panel has got to be modified to accommodate MTP cables. this could price quite LC connectors and regular single mode fiber cables. Besides, it isn't simple to wash MTP connectors. therefore coarse wavelength division multiplexing is additional profitable and fashionable for 40GBASE-LR4 QSFP+ link.

For 40GBASE-LR4 QSFP+ transceivers, each coarse wavelength division multiplexing link and parallel single mode link will reach the transmission distance of ten metric linear unit. 40GBASE-LR4 CWDM QSFP+ transceivers use a duplex LC connection via a pair of optical sm fibers. And 40GBASE-LR4 parallel single mode QSFP+ transceivers use associate MTP/MPO fiber ribbon connection via eight optical sm fibers. Thus, there's no ought to build any changes to upgrade ten G fiber cable plant to forty G property, that is less expensive. Fiberstore provides wide whole compatible forty G coarse wavelength division multiplexing QSFP+ transceivers, like Juniper compatible JNP-QSFP-40G-LR4 and HP compatible JG661A. every fiber optic transceiver has been tested to make sure its compatibility and ability.

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