On September 1 (2016), Mitsubishi Electric Corporation will begin shipping a 25 Gbps distributed feedback (DFB) laser diode. The ML764AA58T diode, which transmits at 1310 nm, was developed for optical links between base stations and central offices in radio access networks. Next-generation mobile networks must support 25 Gbps transmissions, while surviving wide-ranging outdoor environmental conditions.
![ML746AA58T DFB laser.](/ext/resources/images/Newsletters/2016b/Mitsubishi-DFB-laser.png)
The ML764AA58T is packaged in a φ 5.6 mm TO-CAN that suppresses electrical signal loss and meets the compact SFP28 standard for 25 Gbps transceivers. Since no driver IC is used, the size is the same as that of a 10 Gbps DFB laser. The ML764AA58T operates from -20°C to +85°C and can operate outdoors without requiring a cooling system.
According to Wikipedia, a DFB laser is "a type of laser diode, quantum cascade laser or optical fiber laser where the active region of the device is periodically structured as a diffraction grating. The structure builds a one-dimensional interference grating (Bragg scattering), and the grating provides optical feedback for the laser."