Number of Modes calculator uses Number of Modes = (2*pi*Radius of Core*Numerical Aperture)/Wavelength of Light to calculate the Number of Modes, Number of Modes refers to the different spatial propagation paths or patterns that an optical signal can take within a multimode. Number of Modes calculator uses Number of Modes = (2*pi*Radius of Core*Numerical Aperture)/Wavelength of Light to calculate the Number of Modes, Number of Modes refers to the different spatial propagation paths or patterns that an optical signal can take within a multimode. Here we explain in detail how the RP Fiber Calculator software is used. Each of the menu items explains one of the tabs. (Note that cladding modes are not considered — a fiber can have a huge number of these, and their detailed properties. Professional fiber mode analysis calculator. Calculate fiber modes, V-number, and numerical aperture easily. Understand wave guidance using clean, practical inputs today. If you want to go directly to the software, scroll to the bottom, but if you are interested in where these modes come. An optical fiber is essentially a cylindrical waveguide with a core and cladding of different refractive indices. In such a case, light, as it travels through this fiber, undergoes total internal reflection at the interface between the core and cladding, hence guiding the light along the fiber. From these parameters this calculator will tell you numerous capabilities and characteristics of your fiber.