SM Dual Fiber Collimator is the basic element for in-line fiber optics components, such as Circulators and WDM. It has low PDL, low insertion and high return loss. The unique processing and high-quality AR coating also enable this collimator to handle high power. Thorlabs' compact, ultrastable FiberPort micropositioners provide an easy-to-use platform for. Dual Fiber Collimator is an optical device which changes the diverging light from two fibers into a parallel beam, or couples a parallel beam into two fibers, by using a C-lens or G-lens.