CWDM Laser Light Source for wavelengths from 1271nm to 1671nm

Optical fiber component manufacture & test
Optical communication system test
CWDM PLC testing

CWDM

CWDM supports up to 18 wavelength channels transmitted through a fiber at the same time. To achieve this, the different wavelengths of each channel are 20nm apart. DWDM, supports up to 80 simultaneous wavelength channels, with each of the channels only 0.8nm apart. CWDM technology offers a convenient and cost-efficient solution for shorter distances of up to 70 kilometers. For distances between 40 and 70 kilometers, CWDM tends to be limited to supporting eight channels

DWDM

Unlike CWDM, DWDM connections can be amplified and can, therefore, be used for transmitting data much longer distances.

The two key WDM technologies are CWDM and DWDM. Which solution is best suited to a given environment depends on the network and user requirements.

CWDM is being used in cable television networks, where different wavelengths are used for the downstream and upstream signals. In these systems, the wavelengths used are often widely separated. For example, the downstream signal might be at 1310 nm while the upstream signal is at 1550 nm.

Some GBIC and small form factor pluggable (SFP) transceivers utilize standardized CWDM wavelengths. GBIC and SFP CWDM optics allow a legacy switch system to be “converted” to enable wavelength multiplexed transport over a fiber by selecting compatible transceiver wavelengths for use with an inexpensive passive optical multiplexing device.

The 10GBASE-LX4 10 Gbit/s physical layer standard is an example of a CWDM system in which four wavelengths near 1310 nm, each carrying a 3.125 gigabit-per-second (Gbit/s) data stream, are used to carry 10 Gbit/s of aggregate data.

Passive CWDM is an implementation of CWDM that uses no electrical power. It separates the wavelengths using passive optical components such as bandpass filters and prisms. Many manufacturers are promoting passive CWDM to deploy fiber to the home.