Elizabeth F. C. Dreyer

Optical magnetization, Part I: Experiments on radiant optical magnetization in solids.

Linearly-polarized magnetic dipole (MD) scattering as intense as Rayleigh scattering is reported in transparent garnet crystals and fused quartz through a magneto-electric interaction at the molecular level. Radiation patterns in quartz show the strongest optical magnetization relative to electric polarization ever reported. As shown in an accompanying paper, quantitative agreement is achieved with a strong-field, fully-quantized theory of magneto-electric (M-E) interactions in molecular media. The conclusion is reached that magnetic torque enables 2-photon resonance in an EH* process that excites molecular librations and accounts for the observed upper limit on magnetization. Second-order M-E dynamics can also account for unpolarized scattering from high-frequency librations previously ascribed to first-order collision-induced or third-order, all-electric processes.

Optical magnetization, Part II: Theory of induced optical magnetism

A fully quantized analysis is presented on the origin of induced magnetic dipole (MD) scattering in two-level diatomic molecules. The interaction is driven by dual optical fields, E and H*, and is universally allowed in dielectric optical materials, including centrosymmetric media. Leading terms of the interaction are shown to be quadratic and cubic with respect to the intensity, predicting an upper limit for the induced magnetic dipole scattering intensity (IMD∝m2) that is equal to the electric dipole scattering (IED∝p2). The optical dynamics proceed by first establishing an electric polarization in the system. Then the magnetic field exerts torque on the orbital angular momentum of the excited state, mediating an exchange of orbital and rotational angular momenta that enhances the magnetic moment. The magneto-electric interaction also accounts for second-order, unpolarized scattering from high-frequency librations previously ascribed to third-order, all-electric processes.

Celebrating the International Year of Light in Michigan

The 2015 International Year of Light created a wonderful opportunity to bring light and optics events and activities to people of all ages and occupations in Michigan. A large spectrum of events took place; from events held in schools, colleges, and universities targeting various groups of students, to events associated with festivals attended by large crowds. The latter included the Ann Arbor Summer Festival held in June and the Flint Back-to-the-Bricks Festival in August. All events included interactive activities where participants learned hands-on about optics and photonics phenomena and applications. Original demonstrations and kits were developed by the Ann Arbor OSA Local Section and the Optics Society at the University of Michigan, the joint OSA/SPIE student chapter, for use during the events. The activities were funded through the student chapter’s SPIE grant for IYL outreach events and corporate sponsorships. Under the name Michigan Light Project, these groups along with local technology enthusiasts and science clubs delivered several events across Michigan. Other events took place throughout the year in Mid-Michigan through the efforts of faculty and students in the Photonics and Laser Technology program at Baker College of Flint. The outreach events targeted students in K-12. Teachers, counselors, and parents also learned about the importance of optics and photonics in society. The activities developed will continue this year and in the future. The paper will provide details on the completed events and activities along with tips for implementing similar activities and outreach partnerships in other areas.

International Year of Light in Michigan: outdoor holography

Outdoor holography is an activity created by the Michigan Light Project during the International Year of Light. Traditional holography is done in dark and quiet rooms. Using a kit from LitiHolo.com, we designed a way to make simple holograms outside in a noisy festival environment.

Four-fold enhancement of transverse optical magnetism in unstructured solids

Scattering experiments on second-order induced magnetization in transparent Gadolinium Gallium Garnet (GGG) crystals show four times the maximum magnetic response measured previously in liquids.

Erbium distribution in single crystal YAG fibers grown by laser-heated pedestal growth technique

Single crystal (SC) yttrium aluminum garnet (YAG, Y3Al5O12) as a host material has the ability to be doped with high concentrations of Er3+ ions. We utilize this ability to grow a 50% Er3+ doped YAG SC fiber, which was inserted into a SC YAG tube. This rod-in-tube was used as a preform in our laser-heated pedestal growth (LHPG) apparatus to grow a fiber with a radial distribution of Er3+ ions. The work shows that there is a distribution of Er3+ ions from their fluorescence and two different techniques were used to measure the index of refraction.

Nonlinear magnetic scattering from polymer microring resonators

Optical scattering from a high-Q polymer micro-ring resonator shows evidence of intense magnetic interactions due to a second order magneto-electric nonlinearity.

Depolarizing Molecular Rotations in Magneto-Electric Light Scattering

Nonlinear light scattering experiments in solid and liquid dielectrics with a range of electronic structures point to the importance of molecular rotations in enhancing second-order magneto-electric interactions and generating depolarization.