Theoretical and experimental investigation of themagneto-optical eect in graphene in the THz region

Abstract: In many optics applications we need lenses with dynamically tunable focal lengths. One design of such a lensis developed in and it relies on the magneto-optical eect. In this design, a graphene layer is placed ina magnetic eld that varies quadratically in space. During this project I have built an experimental set-upthat can be used to make magneto-optical measurements. The graphene sample is placed in an evacuatedcryostat and it needs to be cooled to low temperatures using liquid nitrogen. The magnetic eld neededfor the measurements is generated by a permanent magnet system placed outside the cryostat. This reportpresents the theory behind the optical magnetic lens, a description of the cryostat and of the steps I tookto design and build the cooling system and the magnet system. Finally, temperature and magnetic eldmeasurements are presented and compared with the values obtained from COMSOL simulations.