Graded Index Multi Mode Fiber

Carbon coating options for reduced hydrogen sensitivity.

Graded index multi mode fiber. Thorlabs graded index grin multimode fiber provides lower modal dispersion and less bend loss than traditional multimode step index fiber with a broad operating wavelength range from 800 1600 nm see the graphs tab for attenuation plots over this range. Graded index multimode fiber. The light wave that travels inside the fiber changes its behaviour with time while travelling inside it. The diameter of core in graded index multimode fiber is somewhat between 50 to 100 micrometer.

Thus 62 5 125 μm multi mode fiber has a core size of 62 5 micrometres μm and a cladding diameter of 125 μm. Multi mode fibers are described by their core and cladding diameters. The transition between the core and cladding can be sharp which is called a step index profile or a gradual transition which is called a graded index profile. Graded index fiber is a type of fiber where the refractive index of the core is uniform at the center core and then it decreases towards core cladding interface.

Graded index fiber is of only one type that is multi mode fiber. Because of the larger core size compared to single mode fiber these fibers provide a higher transmission capacity and are used for short range communication networks and high speed transmission applications. Modal dispersion can be further decreased by selecting a smaller core size less than 5 10μm and forming a single mode step index fiber. The large diameter of the core allows multiple rays to propagate through the fiber.

Graded index multimode optical fibers optimized for signal transmission at 850 and 1300 nm are available with 50 125 62 5 125 and 100 140 µm core cladding diameters. Suitable for light wave communication links and local area networks carrying voice video and data standard and high temperature up to 375 c versions. Multi mode optical fiber can be built with either graded index or step index. This type of fiber is normalized by the international telecommunications union itu t at recommendation g 651 1.

Index profiles is in the shape of a parabolic curve for α 2.