Compositions, optical data storage media and methods for using the optical data storage media

A method, comprising:

• (a) providing an optical data storage medium comprising:
• a polymer matrix;
• a reactant capable of undergoing a photochemical change upon triplet excitation;
• and
• a non-linear sensitizer comprising one or more subphthalocyanine reverse saturable absorbers capable of absorbing incident radiation at 405 nm to cause upper triplet energy transfer to said reactant;
• and
• (b) recording bit-wise a microhologram in said optical data storage medium by irradiating the optical data storage medium with an exposure consisting of an interference pattern having an incident radiation of about 405 nm wavelength, to cause upper triplet energy transfer from the non-linear sensitizer to the reactant, thereby causing the refractive index change,
• wherein the one or more subphthalocyanine reverse saturable absorbers comprise boron (III) subphthalocyanines.