Master of Science
Wierer, Jonathan J.
The rotation of polarization of light as it propagates through a dielectric mediumin a direction parallel to an applied magnetic field is known as the Faraday effect. Theeffect is dispersive and is typically characterized by varying wavelength, temperature,and magnetic field strength. Meticulously collected Faraday effect data exists for manysubstances and has numerous practical uses in materials science and engineering. Forexample, Faraday effect data can be used as a parameter in materials physics calculationsto determine electron and hole effective masses. Also, the effect is utilized in thetelecommunications and laser industry in applications such as isolators and circulatorsbecause of the nonreciprocal nature of the effect.This thesis examines the Faraday effect in Gallium Nitride (GaN) for which littleexperimental data exists, and none within the visible spectrum. Since GaN is a directbandgap material with bandgap emission in the visible range, potentially usefulapplications could be employed if the effect is found to be of sufficient strength (of highVerdet constant). In this work, the Faraday effect was found to exist very strongly inGaN, with a Verdet constant of 72 rad/T-cm at 520 nm and 25 °C. As a comparison,materials produced specifically for this purpose such as terbium gallium garnet used infiber optic components have lower Verdet constants at less than 50 rad/T-cm. However,the cost is presently higher for GaN, so it would not be suitable to replace currentFaraday materials. The high Verdet constant of GaN does provide motivation for furtherstudy though, especially in new potential applications of integrated optical and activedevices which could exploit the strength of this effect at visible wavelengths.
Peart, Matthew R., "The Faraday Effect in Gallium Nitride" (2016). Theses and Dissertations. 2757.
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