C-Lens is specially designed with special material and profile for collimator used in fiber optics. C-Lens can transform the light from single mode fiber into a collimating beam in lower loss (IL, Insertion Loss), than Grin-lens, and perfectly return loss (RL). In reverse, C-Lens also can as a coupler from collimating beam into fiber. C-Lens can be designed for collimator at different working distance.