After several years of experience from partnerships and supporting the OCT and Bio-Imaging communities with customized components and modules, Gould is now releasing it’s commercial line of Fused Dual-Clad Fiber (FDCF) couplers.
The typical 2X2 FDCF couplers have Dual-Clad (DC) fiber in two opposite leads, and multimode (MM) fiber in the other two arms (Fig .1). The DC input fiber can be optionally replaced with a matching single-mode (SM) fiber and the MM output fiber can be terminated to form a 2×1 FDCF coupler (Fig.2).
Light launched in the single mode core of the input SM fiber or DC fiber will transmit 100% through the FDCF coupler directly to the inner core of the output DC fiber while light launched in the inner cladding of the DC fiber will couple to the MM fiber with at least 50% coupling efficiency depending on the core size of the MM fiber as a bigger MM fiber (i.e. 250um core) results in a higher coupling transmission percentage (70% or higher) to the MM fiber. As different DC fibers have different operating wavelength ranges thus proper choice of SM fiber is very important for building a high performance FDCF coupler.
FDCF couplers are used for many applications such as OCT and Super Resolution Imaging, Fiber Sensors, Spectroscopy, Confocal & Fluorescence Microscopy.