The DFB laser series chips supporting 25gb / s lwdm (fine wavelength division multiplexing) 5g forward transmission solution work near the zero dispersion point of o-band, with 800 GHz channel spacing and a total of 12 wavelength channels.
By the end of 2019, China Telecom Research Institute has led the completion of two lwdm standards projects, and in a very short period of time, it has completed discussions on lwdm functional requirements and technical indicators with upstream and downstream manufacturers to form standards and specifications.
In the standard specification, the longest channel wavelength is adjusted from 1332.41nm to 1318.35nm. China Telecom Research Institute has organized a comprehensive test of 5g forward transmission lwdm solution supplied by at least four optical module manufacturers, including conventional performance test and industrial high and low temperature test.
The 25gb / s wavelength channel of lwdm scheme is 1269.23nm ~ 1318.35nm, which is concentrated in the zero dispersion wavelength region of 1310nm, which has obvious advantages of low dispersion cost. It can all adopt low-cost DML laser and pin receiver technology. All wavelength channel optical modules of lwdm are packaged with refrigeration, which can support industrial temperature range.
