Numerical analysis of the transmission efficiency of heat-drawn and chemically etched scanning near-field optical microscopes

The scanning near-field optical microscope (SNOM) has been tested experimen tally for a wide variety of applications, but, to date, there has been litt le work done on the numerical or analytical modeling of the optical held as it propagates throughout the SNOM probe. Therefore, the fabrication on the probes relies more on trial and error than on dear design principles. An a lgorithm has been developed for the study and optimization of the geometry of SNOM probes fabricated by the heat-drawn and the one-step chemically etc hed methods. The algorithm uses the finite-difference beam propagation meth od (FDBPM) to model the field evolution throughout the SNOM structure. (C) 2000 Optical Society of America.