A near field optical microscope with a scanning area up to1 mm×1 mmwas demonstrated. The scanning element is the tapered fiber probe and a cylindrical lens is used to focus the feedback laser. Instead of the vibrational amplitude, the vibrational angle signal is used to regulate the distance between the probe and sample. The microscope was employed to map out the evanescent wave on a channel waveguide. ©1998 American Institute of Physics.