Wavelength division multiplexers (WDM) are used to combine two or more optical carrier signals of different wavelengths (carrying various information) at the sending end through a multiplexer (also known as a multiplexer), and coupled to the same optical fiber of the optical line for transmission; at the receiving end, the optical carriers of various wavelengths are separated by a demultiplexer (also known as a demultiplexer or a demultiplexer), and then transmitted by the optical the receiver performs further processing to recover the original signal. This technology of simultaneously transmitting two or more optical signals of different wavelengths in the same optical fiber is called wavelength division multiplexing.

Coarse wavelength division multiplexing (CWDM) uses a wide window of 1200 to 1700nm, and mainly used in systems with a wavelength of 1550nm. Of course, a wavelength division multiplexer with a wavelength of 1310nm is also under development. The distance between adjacent channels of a coarse wavelength division multiplexer (large wavelength interval) is generally ≥20nm, and the number of wavelengths is generally 4 or 8, up to 16. When the number of multiplexed channels is 16 or less, since the DFB laser used in the CWDM system does not require cooling, the CWDM system has more advantages than the DWDM system in terms of cost, power consumption requirements and equipment size, and CWDM is widely used and accepted by the industry.

Dense wavelength division multiplexing (DWDM) can carry 8 to 160 wavelengths, and with the continuous development of DWDM technology, the upper limit of its demultiplexed wave number is still increasing, and the interval is generally ≤1.6nm. It is mainly used in long-distance distance transmission system. Dispersion compensation technology is needed in all DWDM systems (to overcome nonlinear distortion in multi-wavelength systems-four-wave mixing phenomenon). In the 16-wave DWDM system, the conventional dispersion compensation fiber is generally used for compensation, while in the 40-wave DWDM system, the dispersion slope compensation fiber must be used for compensation. DWDM can combine and transmit different wavelengths in the same optical fiber at the same time. In order to ensure effective transmission, one optical fiber is converted into multiple virtual optical fibers.

Applications:

● High-speed transceiver;

● WDM PON network;

● 5G fronthaul and metropolitan area network;

● Instruments and laboratories.

Typical product:

1.1550 ±2.0 nm single F-P cavity filter;<0.5dB peak loss;10±1 nm FWHM linewidth;<0.2pm/°C thermal shift;4.0±0.1x4.0±0.1x1.0±0.1 mm in sizes;> 3 mm dia. clear aperture and backside AR coating: R<0.25%over 1520-1570 nm

2.1550 ±2.0 nm single F-P cavity filter;<0.5.dB peak loss;15±1nm FWHM line width<0.2pm/°C thermal shift;4.0±0.1x4.0±0.1x1.0±0.1 mm in sizes;> 3 mm dia. clear aperture and backside AR coating: R<0.25%over 1520-1570 nm

3.1332±2 nm CWL hard coating  single cavity bandpass filter; 1.2+0.05/-0.01 nm FWHM linewidth; <0.5dB peak loss; backside AR coating over 1280/1335 nm;  < 4pm/C thermal wavelenght drift; < 300pm trans. wavlength uniformity over 3 mm clear aperture; 1.0±0.1mm thickness, 4.0±0.2 mm square. 

4.1310 ± 2 nm central wavelength;2) Peak loss <0.5 dB;3) 0.6 ± 0.05 nm FWHM linewidth single cavity filter;4) <4.0 pm/C thermal wavelength shift;5) 0 to 70 C operating temperature;6) Thickness 1.0 +/- 0.1 mm7).Clear aperture 3 mm;

Coating Curve: