FBT Coupler

FBT (Fused Biconical Tapered) couplers are the right tool when you need a non-standard split ratio, single-wavelength performance, or extreme cost efficiency at low port counts. Two or more fiber cores are heated, twisted, and drawn down to a precise coupling region — yielding a passive device with no chip, no waveguide, and excellent power-handling characteristics. Optiunik produces 1×2 and 2×2 FBT couplers at any customer-specified split ratio (50/50, 70/30, 80/20, 90/10, 95/5, 99/1, etc.), for 1310 nm, 1490 nm, 1550 nm, or dual-window 1310/1550 nm operation. Typical excess loss is < 0.1 dB, directivity > 55 dB, PDL < 0.1 dB, and operating temperature -40 to +85 °C. Units are GR-1209 / GR-1221 tested and ship with an individual data sheet.