On-demand tapered optical fiber

Tapering optical fibers to create nanofibers with submicron diameters enables strong light confinement and enhances nonlinear effects. However, a key challenge in this process is maintaining guided optical modes and minimizing optical losses. Losses primarily arise from mode leakage in the transition regions connecting the standard fiber to the nanofiber. The geometry of these transitions is crucial for ensuring adiabatic mode evolution and achieving low-loss transmission. Current tapering techniques offer limited flexibility in shaping these transitions, restricting optimization. This work introduces a novel approach to fiber tapering using a classical fusion-heat-brush process. This method allows for precise control over the transition shape, enabling fabrication of nanofibers with transitions defined by any decreasing function. By offering enhanced design flexibility, this technique expands the potential applications of optical nanofibers in nonlinear optics and signal processing.