Carbon nanotube-doped polymer optical fiber

Carbon nanotube/polymer composite coated tapered fiber for four wave mixing based wavelength conversion

In this paper, we demonstrate a nonlinear optical device based on a fiber taper coated with a carbon nanotube (CNT)/polymer composite. Using this device, four wave mixing (FWM) based wavelength conversion of 10 Gb/s Non-return-to-zero signal is achieved. In addition, we investigate wavelength tuning, two photon absorption and estimate the effective nonlinear coefficient of the CNTs embedded in the tapered fiber to be 1816.8 W(-1)km(-1).

Optical deposition of graphene and carbon nanotubes in a fiber ferrule for passive mode-locked lasing

Mode-locked fiber lasers are currently undergoing a significant evolution towards higher pulse energies and shorter pulse durations. A key enabler in this progress has been the discovery of novel saturable absorbers (SA) such as carbon nanotubes (CNT) and graphene. The exceptional properties of CNTs as SA have been extensively studied in recent years. Graphene, a one atom thick planar sheet of carbon atoms arranged into a hexagonal lattice, has been recently proposed as an alternative to CNTs in several photonics applications. Here, we propose a method for the integration of graphene into a fiber ferrule using an optical deposition technique, which has been also employed for the deposition of CNT directly on the core of a fiber edge and in tapered fibers. We investigate and compare the optical properties of CNT-SA and graphene-SA fabricated by this optical deposition technique. Soliton-like, mode-locked lasing is confirmed using an erbium doped optical fiber in an all-fiber ring cavity laser configuration.

Passive mode-locked lasing by injecting a carbon nanotube-solution in the core of an optical fiber

In this paper, we propose a saturable absorber (SA) device consisting on an in-fiber micro-slot inscribed by femtosecond laser micro fabrication, filled by a dispersion of Carbon Nanotubes (CNT). Due to the flexibility of the fabrication method, efficient and simple integration of the mode-locking device directly into the optical fiber is achieved. Furthermore, the fabrication process offers a high level of control over the dimensions and location of the micro-slots. We apply this fabrication flexibility to extend the interaction length between the CNT and the propagating optical field along the optical fiber, hence enhancing the nonlinearity of the device. Furthermore, the method allows the fabrication of devices that operate by either a direct field interaction (when the central peak of the propagating optical mode passes through the nonlinear media) or an evanescent field interaction (only a fraction of the optical mode interacts with the CNT). In this paper, several devices with different interaction lengths and interaction regimes are investigated. Self-starting passively modelocked laser operation with an enhanced nonlinear interaction is observed using CNT-based SAs in both interaction regimes. This method constitutes a simple and suitable approach to integrate the CNT into the optical system as well as enhancing the optical nonlinearity of CNT-based photonic devices.

A 113 fs fiber laser operating at 1.56 mum using a cascadable film-type saturable absorber with P3HT-incorporated single-wall carbon nanotubes coated on polyamide

We successfully fabricated a cascadable film-type single-wall carbon nanotube (SWNT) saturable absorber coated on aromatic polyamide film, in which the saturable absorption effect can be controlled with the number of films. A conductive polymer P3HT (poly-3-hexylthiophene) was adopted to obtain a uniform SWNT solution. We applied saturable absorber films to a passively mode-locked fiber laser and successfully generated a 113 fs, 42 MHz pulse by inserting two film layers between fiber connectors in the cavity.