Nanowire Optical Waveguide: Mode Confinement

A semiconductor nanowire is thin enough that it doesn't just carry current — it guides light, exactly like a miniature optical fiber. This simulator models a single nanowire (Si, GaAs, InP, GaN or ZnO) suspended in air as a real step-index cylindrical waveguide: pick a radius and a wavelength, and watch the dimensionless V-number cross the Bessel-zero cutoffs that switch each guided mode (LP01, LP11, LP21, LP02) on or off. A 3D field-intensity render shows exactly how tightly each mode's light is held inside the core versus how far its evanescent tail leaks into the surrounding air, while live readouts track the V-number, the count of currently-guided modes, and the effective refractive index the selected mode actually experiences. This is the same confinement physics that determines whether a real nanowire behaves as a single-mode waveguide for a nanowire laser or LED, or a multimode one for a broadband photodetector.