2x2, 830nm, 80/20 split ratio pigtail fused coupler with 250um OD buffered 5/125 SM fiber terminated with Angled FC/PC connectors on the two input ports, while the 2 output ports are terminated with 12mm diameter collimators using f=16 NIR achromat lenses. The fiber on the input port (port T) is 260±5mm long. The fiber on the 80% output port (Port 1) is 650±5mm long. The fiber on the 20% port (port 2) is 515±5mm long . The fiber on the return port (port R) is 700±10mm long and.put 600mm long 0.9mm OD tubing from FC boot end .SP2: (1) The length difference between the port 1 fibers and port 2 fibers is to be 135mm ± 5mm. (2) The collimator barrels will be 40mm long, not 50mm. (3) The output beam is centered to better than 1mrad.
