Tap coupler and photodiode
The TAPD is a tap coupler module with an InGaAs photodiode as a monitoring device for use with DWDM systems operating in the 1550-nm signal band. The device has a dimension of 725 mm. The wavelength dependence and temperature dependence of the tap coupler is #0.35 dB at 1540 to 1560 nm and 0! to 70!C (the tap ratio is 5%).