S. Rodrigues

Supercontinuum generation in chalcogenide layered spiral microstructured optical fiber

The layered spiral microstructured optical fiber (LS-MOF) design allows higher nonlinearities than the most common microstructured optical fibers. Here, we have chosen a highly nonlinear glass for its composition, the arsenic trisulfide, and we have determined its dispersion and nonlinear characteristics. After adjusting the fiber’s parameters, we obtained a record value for the nonlinear parameter of 50.7W−1m−1, at 1.550μm. We have simulated light propagation under these optimized circumstances, achieving a broad supercontinuum, extending from 500nm to 3900nm, in a very short distance: 0.3mm.

Ultraviolet Light Generation in Gas-Filled Kagome Photonic Crystal Fiber

Abstract Kagome hollow-core photonic crystal fibers were found to be ideal for the occurrence of ultrafast non-linear optics. This article reports the optimal conditions for the generation of ultraviolet light using a gas filled kagome hollow-core-photonic crystal fiber. It is shown that by changing the pressure of the gas and the input pulse characteristics, the efficiency of conversion and quality of ultraviolet light can be improved, as well as tuning its central frequency. Results suggest that a highly coherent and tunable ultraviolet light source can be constructed, which can find numerous applications.

Continuous wave supercontinuum generation aided by a weaker pulse laser

The supercontinum generation has been achieved mainly by two different approaches, namely, with femtosecond intense pulses or using a continuous wave laser or larger pulses centered on the anomalous dispersion region. In order to improve temporal coherence, it has been suggested the introduction of a pulse seed or the propagation of both a large pulse pump and a small weaker continuous wave to control the soliton fission. Here we propose supercontinuum generation using a hybrid input, we pump with a continuous laser and copropagate a picosecond signal. We compare the bandwidth of the supercontinuum using only the continuous pump or the hybrid setup. Simulations of the generalized Schrodinger equation, using an adequate input-noise model to reproduce the spectrum of the continuous signal, are performed in order to investigate the supercontinuum generation in the optical communication window under different dispersion regimes.

Experimental setup for electromagnetically induced transparency observation in hollow-core fibers

We developed a system to investigate resonant nonlinear optical interactions in acetylene molecules, confined in a hollow-core photonic crystal fiber (HC-PCF), using light injection through a low-loss splice from one end of the fiber, allowing us to work at low power. Electromagnetically induced transparency (EIT) was observed in the 1500 nm telecommunications window.

Design of microstructured optical fibers for supercontinuum generation

The optimized design of microstructured optical fibers (MOFs) for supercontinuum generation is investigated. The dependence of the group velocity dispersion and effective mode area on wavelength is analyzed. We consider first the case of a conventional MOF with a hexagonal pattern of air holes. In addition, we propose a new design, corresponding to a layered spiral microstructured optical fiber (LS-MOF). By changing appropriately its three parameters, it is possible to shift the zero dispersion wavelength to visible and near-infrared regions, as well as to achieve a very high nonlinearity near this wavelength. Supercontinuum generation is simulated in a LS-MOF with optimized design .