There are two techniques of division multiplexing wavelength which means transmitting signals via optical fiber. They are DWDM and CWDM.

DWDM--Dense Wavelength Division Multiplexing means division multiplexing in dense wave longitude. DWDM transmission technique through optical fiber using the C band (1550 nm). That is a multiplexing method very similar to the frequency division multiplexing is used in electromagnetic transmission means. Several carrier signals (optical) are transmitted by a single optical fiber using different wavelengths of laser beam each. Each optical carrier is an optical channel that can be treated independently of other channels that share the medium (fiber optic) and contain different types of traffic. In this way can multiply the effective bandwidth of the optical fiber, so as to provide bidirectional communications. This is a very attractive transmission technique for telecom operators by allowing them to increase capacity without additional wiring or trenching. To transmit using DWDM is needed from complementary devices: a transmitter side muxer y demuxer at a receiver side it. Unlike him CWDM, DWDM is in numbers mayor Get optical channels reducing the chromatic dispersion of each channel through it using a laser Mayor Quality, baja fiber dispersion through him the use of DCM modules Dispersion Compensation Modules. In this MANERO you can combine more channels reducing space between he ello. Currently it pueden get 40, 80 to 160 optical channels separated 100 GHz, 50 GHz to 25 GHz respectively.

CWDM--Coarse Wavelength Division Multiplexing originally was fairly generic, and meant a number of different things. In general, these things shared the fact that the choice of channel spacings and frequency stability was such that erbium doped fiber amplifiers (EDFAs) could not be utilized. Prior to the relatively recent ITU standardization of the term, one common meaning for coarse WDM meant two (or possibly more) signals multiplexed onto a single fiber, where one signal was in the 1550 nm band, and the other in the 1310 nm band. CWDM Multiplexer Modules are available in 4, 8 and 16 channel configurations. These modules passively multiplex the optical signal outputs from 4 or more electronic devices, send them over a single optical fiber and then de-multiplex the signals into separate, distinct signals for input into electronic devices at the other end of the fiber optic link. The Coarse Wavelength Division Multiplexing-CWDM Mux/demux are a flexible plug-and-play network solution, which allows service providers and enterprise companies to cost effectively implement point to point or ring based WDM optical networks. CWDM Mux/demux is modular, scalable and is perfectly suited to transport PDH, SDH / SONET, ETHERNET services over WWDM, CWDM and DWDM in optical metro edge and access networks.

For a new year gift, here is some imformation of a fiber optic machine for you. It may be a necessity in you work--a variable optical attenuator. Optical variable attenuator is a double window (1310/1550nm) of passive components. The variable optical attenuator could continually and variably attenuate the light intensity in the optical fiber transmission. Variable fiber optic attenuator could help simulate distance or actual attenuation in the fiber optic testing work by inserting a calibrated attenuation into the link. By using the variable fiber optic attenuator, technicians could verify the power margin received by testing the fiber optic link power budget. Variable fiber attenuator can help user vary the light power injected from a light source into the optical fiber. Important parameter of variable fiber attenuator include its insertion loss, reflection loss and attenuation range. We supply ST, FC, SC, LC variable fiber optic attenuators with APC, UPC type. Attenuation range available is from 1dB to 30dB.