A simple submicron confocal microscope with a fiberoptic output

We present a simple design of a reflection-type confocal microscope with a multimode graded-index fiber output. Due to the use of an apertureless confocal arrangement, a high-aperture focusing objective and a large-core graded-index multimode fiber for signal detection, a regime of high-output power is achieved that provides high resolving power and submicron spatial resolution. The graded-index multimode fiber ensures an efficient launching and maintenance of high laser powers, a high sensitivity to spatial displacements of the focusing backreflectance emission, and a low mode noise and signal fluctuations. At axial scanning of the test object, a submicron resolution of 0.4 μm is obtained.