Basic concept of light module

1. Laser category

Laser is the core device in the optical module. The current is injected into the semiconductor material and the laser is emitted through the photon oscillation and gain of the resonant cavity. At present, the most commonly used laser is FP and DFB laser. Their difference is that the semiconductor material has different resonance cavity structures. The price of DFB laser is much more expensive than FP laser. The light module with a transmission distance within 40km generally uses an FP laser; the transmission distance ≥ 40km light module generally uses a DFB laser.

2. Losses and scattered

Losses is that when light is transmitted in optical fibers, due to the absorption of scattering of the medium and the loss of light energy caused by leakage, this part of the energy is dissipated with a certain ratio as the transmission distance increases. The production of color scattered is mainly because the electromagnetic wave of different wavelengths varies in the same medium when it is transmitted in the same medium, which causes the different wavelength components of the light signal to reach the receiving end at different times due to the accumulation of the transmission distance. value. These two parameters mainly affect the transmission distance of the optical module. In the actual application process, the 1310nm light module is generally at 0.35dBM/KM calculation link loss. Very complicated, generally only for reference.

3. Lauding light power and receiving sensitivity

The transmitting optical power refers to the output light power of the light source of the light source, and the receiving sensitivity refers to the minimum receiving light power of the light module under a certain rate and the misunderstanding. The units of these two parameters are DBM (meaning a decibels, the number of power units MW, the calculation formula is 10lg, and 1MW is converted to 0dbm), which is mainly used to define the transmission distance of the product, different wavelengths, transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates and transmission rates. The optical module of the transmission distance is different and the receiving sensitivity will be different, as long as it can ensure the transmission distance.

4. The service life of the light module

International unified standards, 50,000 hours (equivalent to 5 years) without interruption (equivalent to 5 years).

The SFP light modules are all LC interfaces. The GBIC light modules are SC interfaces. Other interfaces include FC and ST.