Electro-optic interferential quenching of light scattering is observed in microsphere and nematic liquid-crystal dispersions. The used drop-filled and nonaligned liquid-crystal matrix allows the formation of large orientational clusters responsible for this phenomenon, which is interpreted according to the single-scattering model.

It often takes one single event to interest teenagers in a topic that will become a passion or a career. It is in this spirit that the SPIE and OSA Student Chapters at Université Laval created the Photonic Games three years ago, to kindle an interest in teenagers towards studies and careers in optics. The activity, offered each year to more than a hundred grade 11 students, is divided in two parts. First, we offer a hands-on workshop in their classrooms about reflection, refraction, dispersion, birefringence and polarization. A few days later, all the students come to the Centre d'optique, photonique et laser (COPL) at Université Laval for a day of competition where a volunteer physics student accompanies each team of four students. Challenges are various to promote the qualities that make great scientists: creativity, teamwork, knowledge, inquisitiveness, self-confidence and perseverance. The first two editions of the Photonic Games have proven to be beneficial for the students, teachers and volunteers, and we endeavor to improve it as we construct on our experience with the past editions to fine-tune and improve the Photonic Games concept.

Molecular orientation clusters are created in a cell of non aligned liquid crystal to study the light propagation in electrically controllable anisotropic non uniform media. Coherent scattering phenomenon and predominant role of large orientation clusters in such scattering are demonstrated. Fast relaxation of molecular orientation and modulation of light scattering in those clusters is obtained by using ''dual frequency'' liquid crystal mixtures and frequency modulation of the drive signal. The obtained results show the good potential for the creation of electrically tunable tissue models by using liquid crystalline materials.

We report on the study of light polarization behavior in random anisotropy scattering media. It is shown that, in the case of low scattering events, the degree of polarization (DOP) demonstrates oscillatory behavior due to the coherent character of light scattering. A strong increase in the DOP is demonstrated by using electro-optic fine tuning of the refractive index modulation depth of the scattering media.

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