Optical memories, method for reading and writing such optical memories, and device for reading and writing such memories

The invention concerns a optical data memory, said memory comprising at least one layer of supporting material, said supporting material including molecules having, in a local zone, a collective state of molecules from at least one first collective state of molecules, and a second collective state of molecules. The invention is characterized in that only molecules having the first collective state of molecules in said local zone are capable of generating a second-harmonic signal when they are excited in said local zone by a reading electromagnetic radiation

Refractive-index saturation-mediated multiple line emission in polymer thin-film distributed-feedback lasers.

We report experimental and theoretical investigations of multiple laser-line emission in a distributed-feedback dye laser pumped by two coherent optical beams. We have used a Lloyd interferometer configuration with second- and third-order Bragg reflections to study the interaction between the two incident pumps in an organic thin film. We demonstrated theoretically that the number of laser emission lines can be interpreted with reference to the saturation effect in the refractive index

Control of the Refractive Index in Photopolymerizable Materials for (2+1)D Solitary Wave Guide Formation

We report an experimental and theoretical study on the optimization of (2+1)D self-written waveguide formation inside a photopolymerizable material. The accurate control of the refractive index value inside the bulk of the material during the polymerization process gives us the opportunity to define a virtual core and a virtual cladding for the system. The V value which characterizes the guidance properties of a fiber can be applied to this propagation. The control of the V value allows us to propagate single mode or multimode waveguides on a few centimeters. Numerical simulations of these waveguides based on a paraxial model including both photopolymerization and Kerr effect give very good agreement with our experimental results