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Here we investigate the third-order Nonlinear Optical (NLO) properties of Layered Transition Metal Dichalcogenides (LTMDs), the metallic NbS2. The Z-scan technique was employed to characterize the nonlinear refraction (NLR) and nonlinear absorption (NLA) behavior in the picosecond regime.

In this work, we developed and investigated a random laser (RL) based on Rhodamine6G (Rh6G) in ethanol solution with quartzite nanoparticles as scatters in the lasing media.

We report on second harmonic generation from MoS2/WS2 as-grown heterostructures. The two crystal structures naturally align with 0° and ^60. twist angles. While the former enhances, the latter decreases the nonlinearity from individual layers.

In this work, we developed and investigated a random laser based on rhodamine6G (Rh6G) in ethylene glycol (EG) solution with varying cellulose nanocrystalline (CNC) needles as scatterers in the lasing media. Besides the suspension-in-cuvette scheme, an alternative configuration was also employed: a dye-CNC flexible self-supported thick-film (70 µm) random laser made by drop casting of the C N C s + R h 6 G + h y d r o x y p r o p y l cellulose suspension. In relation to conventional scatterers, the biodegradable cellulose nanocompounds showed a comparable reduction in both the spectral full width at half-maximum and the energy threshold values, with an optimal concentration of 5 mg [CNC]/ml[EG] in suspension. Its performance was also compared with other cellulose-based random lasers, presenting advantages for some parameters. The flexible film configuration showed similar results, but contained 10% less Rh6G than the suspension.

In-fiber modulators are extremely attractive for telecommunication applications, and electro-thermal polin can be used to induce the necessary second-order nonlinearity in the glass fiber [1]. Long et al. have recently reported a way of mounting and poling D-fibers that is extensible to volume manufacturing and a relatively low voltage modulator has been demonstrated [2]. D-fibers are rugged, particularly if inbeded i a resin such as polyimide, but restrict the choice of available fibers, are not easily spliced, and a part of the voltage applied externally is wasted in biasing the cladding, unless further polishing/etching is used to remove the cladding and leave only the core region of the fiber. In the present work, we describe an alternative approach to making a fiber modulator, where pieces of conventional fiber are used, the central part of which is etched to the core and subsequently poled. After etching, the fibers have a diameter of ~10 μm and therefore are referred to as microfibers. Microfibers are surprisingly strong for their diameter and have some unique advantages. They can be fabricated with any fiber, the two ends that are not etched are truly easily spliceable, and the applied voltage during poling and in later use of the modulator develops mainly in the core, ensuring a large overlap integral.

Soft glasses, such as soda lime are the often used in waveguide fabrication by ion exchange. They are also cheap, readily available, and are potentially a base material for active components in fiber-to-the-home systems. Therefore, waveguide modulators based on poled soda lime glass are of great interest. In this work we demonstrate that it is possible to induce a large second-order optical nonlinearity in soda lime and borosilicate glass with the electro-thermal poling procedure described by Myers et al1. We also demonstrate a scheme based on poling to record single-mode waveguides in soda lime.

It is now generally believed that second harmonic generation in an optical fiber can be attributed to the creation of a permanent dc electric field grating along the fiber. The grating allows for quasi phase matching and gives rise to high conversion efficiencies. Imaging the grating with micrometer spatial resolution has so far been a difficult task because the cladding of the fiber shields efficiently the core from the environment. Indirect techniques have been employed, such as probing the small changes in the spontaneous Raman spectrum scattered as side-light1. Besides being of difficult interpretation, such technique gives low signal-to-noise ratio measurements.