A fiber collimator is a fiber assembly designed to collimate or focus light at the fiber end. It typically consists of: Optical fiber section – single-mode fiber (SMF) is most common, but polarization-maintaining (PMF) or multimode fiber (MMF) can also be used. Our Polaris ® Kinematic Collimators offer high-quality. In practice, it is often convenient to do this with a fiber collimator (fiber-optic collimator). Most laser collimators use one or more lenses—or sometimes mirrors—to focus. Fiber optic collimators (also called fiber-optic collimators) are crucial optical components that convert the diverging output from an optical fiber into a collimated (parallel) beam, or conversely focus light from free space into a fiber.