Block copolymers are nowadays recognized as powerful tools for the preparation of high value materials. Their ability to spontaneously and reversibly arrange themselves (self- assembly process) allows the production of well-ordered nanostructures in bulk or in solution. In the last decades, extensive effort was given to study the self-assembly of block copolymer in solution since the nanostuctures obtained (micelles) may be used in the chemical, biomedical and pharmaceutical fields. Indeed, such type of structures may act as transportation vector, for the drug or gene delivery, or as a sensing devise, for diagnostic applications. To this end, the appearance in the mid 90's of "smart" or stimuli-responsive polymers has dramatically enhanced the potential of polymeric micelles since the nanostructures can modulate their behavior based on environmental constraints. This thesis focuses on light responsive block copolymers and on the use of light to promote the formation of functional nanostructures in solution. The first part of this thesis deals the synthesis of block copolymers containing one or more photocleavable moieties, either o-nitrobenzyl esters or phenacyl esters. The second part of the thesis focuses on the use light to promote the micellization of block copolymers bearing photocleavable side groups. The third part focuses on the antagonist process where light is used to induce the disruption of micelles made of a photocleavable core and a thermo-responsive corona. Finally, linear photocleavable block copolymers are used as precursors of hollow nanocapsules (nanocages).