1550nm PIN photodiode and 1610nm laser diode assembly is often used in RFoG (radio frequency over glass) networks.

RFoG is an improved design for conventional HFC (hybrid fiber coaxial) networks. RFoG replaces RF coaxial links with optical fiber. A RFoG link uses 1550nm as downstream wavelength. The 1550nm wavelength is loaded with digital (data) and analog (video) services offered to end users by service provider. The reason for using 1550nm is that it offers an option for using optical fiber amplifier (EDFA) to boost its optical power. This helps the downstream light reach more subscribers (that comes with higher optical loss because the light passes through more optical splitters in order to be shared with more end users), or transmit to longer distance.

Other wavelengths such as 1310nm, 1590nm or 1610nm is used as the return path wavelength. The use of different wavelength at the return pass enables bi-directional transmission over the same optical fiber. WDM couplers at both ends of the link are used to separate the return path wavelength with 1550nm.

With RFoG, the bandwidth of downstream as well as upstream is expanded significantly. There is also great potential in expanding the coverage and reach of the network. The use of 1610nm at the return path makes the network compatible with other FTTH designs such as triplexer FTTH networks using 1310nm, 1490nm etc., when the network is fully upgraded to PON.

Our 1610nm laser diode + 1550nm PIN photodiode assembly supports 2.5Gbps bit rate for Tx and Rx of the RFoG ONU (optical network unit).