Views: 0 Author: Site Editor Publish Time: 2023-06-25 Origin: Site
Recently, many colleagues have reported that customers need to learn more about the technical knowledge of FP and DFB lasers, as well as the differences between them. To facilitate explanation to the customer, briefly summarize the knowledge of FP and DFB lasers.
FP laser
FP (Fabry Perot) laser is a semiconductor light-emitting device that emits multi longitudinal mode coherent light with FP cavity as resonant cavity. FP lasers are mainly used for low speed and short distance transmission. For example, the transmission distance is generally within 20km and the transmission rate is generally within 1.25G. FP has two wavelengths, 1310nm/1550nm.
At present, some manufacturers in the market use FP equipment to manufacture gigabit 40km Optical module to reduce costs. In order to achieve the corresponding transmission distance, it is necessary to increase the transmission optical power. Long working hours can lead to premature aging of product equipment and shorten its service life. According to the engineer's suggestion, it is safer to use DFB equipment for 1.25G 40km dual Optical module!
FP laser performance parameters:
1) Working wavelength: The central wavelength of the laser emission spectrum.
2) Spectral width: The root mean square spectral width of a multi longitudinal mode laser.
3) Threshold current: When the operating current of the device exceeds the threshold current, the laser emits a laser with good coherence.
4) Output optical power: The optical power emitted by the laser output port.
