Block copolymer nanostructures mapped by far-field optics.

We demonstrate stimulated emission depletion microscopy using opposing objective lenses to noninvasively reveal the nanoscale morphology of block copolymers in three dimensions with focused light. This is exemplified in a poly(styrene-block-2-vinylpyridine) model system in which contrast is achieved by specifically staining the vinylpyridine phase with a fluorescent dye. We image swelling induced mesopores and other convoluted structures within the bulk of samples, at scales that have so far required electron and scanning probe microscopes.