Simulation and optimization of pyramidal AlGaAs probe with ultra-small spot size and high throughput

In this paper, the light-emitting spot sizes and throughputs of the four types of probes are studied using the finite-difference time-domain method, and these probes are also compared in performance. Among these probes, a pyramidal AlGaAs tip coated entirely with a thin Ag film can provide the highest throughput and a single near-field spot size. Probe coated with a 3nm Ag film and incident light with a wavelength of 800nm seems to offer the optimum condition for high throughput and ultra-small spot size, which enables the realization of ultra-high density storage.