Graphene nanomaterials exhibit excellent optical properties when interacting with electromagnetical fields, which plays an important role in a wide range of applications such as optical communications, optical storage and other fields. Based on the electromagnetically induced transparency (EIT) effect, we investigate control of slow light in the Landau quantized graphene system with different three-level and four-level coupling schemes. Utilizing the EIT effect, group velocity of the probe fields can be significantly reduced and well controlled by manipulating Rabi frequencies and detunings of the coupling lasers as well as probe detuning. Furthermore, probe light with different frequencies can even be controlled in different EIT windows in the graphene system with the four-level scheme, which may find applications in signal selection and discrimination. This work can provide reference for the design of graphene-based quantum devices and have potential applications in optical communications and optical quantum information processing, etc.
The photoinduced birefringence effect in a type of azo-dye-doped poly (methyl methacrylate) was realized when it was pumped by a polarized argon ion laser beam. The transmission of a 632.8 nm probe beam through the pumped sample could be controlled by two kinds of methods: one employed the photoinduced thermal effect of the pump light in the azo-dye-containing sample, and the other changed the temperature of the sample directly. The tunable transmission of the probe light with different pump power and at various temperatures of the sample was investigated in detail.
Amorphous bulk composites were prepared by doping azo-dye Disperse Red 13 (DR13) in poly(methyl methacrylate) (PMMA) matrices. Photo-induced anisotropy of such kind of bulk polymer material was investigated experimentally by measuring the birefringence when irradiating it with linearly polarized green light. We report the first observation of self-trapping of an optical vortex based on such effect in bulk poly(methyl methacrylate) materials containing photosensitive azo-dye molecules. The dependence of the average core width of a single-charge optical vortex versus time and input power was investigated in detail.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.