single mode wideband fiber coupler applications: 1, catv 2, lan, access network 3, telecom, optic fiber communication system 4, ftth 5, monitoring system 6, optic fiber sensor 7, testing devices features: 1, low excess loss 2, customized packaging available 3, environmentally stable 4, high return loss 5, low pdl technical---1 to 2 and 2 to 2 as an example: 1, wavelength, 1310nm or 1550nm, 1310nm and 1550nm 2, bandwidth, more or less than 20nm 3, ratio, 1% to 99% 4, excess loss, less than 0.15db 5, insertion loss, please refer to the coupling ratio 6, pdl, less than 0.10db 7, directivity, less than 60db 8, thermal stability, less than 0.002 db per degree 9, operating temperature, -40degree to +80 degree 10, storage temperature, -40degree to +85degree 11, fiber type, naked fiber, loose fiber or cable 12, fiber length, user-defined 13, port configuration, 1 to 2, 2 to 2 or user-defined