Optical active gallium arsenide cantilever probes for combined scanning near-field optical microscopy and scanning force microscopy

The fabrication process of a GaAs cantilever probe with an integrated vertical cavity surface emitting laser (VCSEL) for scanning near-field optical microscopy applications is described. The VCSEL illuminates an aperture in a thin Au/Ge metallization layer at the tip apex. The light emitting aperture serves as a subwavelength light source and thus can be used to reduce the lateral resolution in transmission imaging beyond the far-field diffraction limit. The light beam of the VCSEL emitted to the opposite side is exploited for the detection of the mechanical deflection of the cantilever that additionally facilitates the scanning force microscopy setup.