Fiber laser technology is attracting a great deal of attention due to its numerous applications in fields as diverse as micromachining, biology and medical sciences or telecommunications and its potential as a substitute for solid-state lasers in industrial and technological applications. Fiber lasers are also exciting from the scientific point of view as they are an excellent platform to further study and understand nonlinear optical phenomena. In this chapter, we review the impact of nano-materials, such as graphene and carbon nanotubes, in advancing fiber laser technology. Both graphene and carbon nanotubes present a highly nonlinear optical response, with a high third order susceptibility and saturable absorption. Here, we discuss how these properties can be used to achieve pulse operation using a technique known as mode-locking and how these two materials compare to other mode-locking mechanisms in terms of their ability to achieve pulse operation, the stability of the mode-locked lasers and their long-term reliability.

Carbon nanotubes have been explored in light-harvesting and photovoltaic devices because of their unique optoelectronic properties. This chapter provides a brief description of the optoelectronic properties of carbon nanotubes, particularly single-wall carbon nanotubes (SWCNTs), and their implication in various solar cell applications including donor–acceptor solar cells, polymer solar cells, and dye-sensitized solar cells, where carbon nanotubes are utilized as photoactive materials. Carbon-nanotube-based electrodes in photovoltaic devices are also introduced. Carbon-nanotube-based light-harvesting devices are reviewed in terms of fabrication and material processing as well as performance. Finally, advanced emerging methods and the future outlook for carbon-nanotube-based solar cells are discussed.

The fundamental electronic states and optical properties of single-walled carbon nanotubes are briefly explained in this chapter. Moreover, the novel optical properties of carbon nanotubes revealed by advanced laser spectroscopy (single-nanotube spectroscopy and time-resolved spectroscopy) are introduced. Due to the enhanced Coulomb interaction, the optically generated electron-hole pair forms a strongly bound ‘exciton’ state, analogous to the hydrogen-like state in the carbon nanotubes. The striking features of excitons in the carbon nanotube, such as singlet-dark states and triplet states, which dominate the optical properties, are described in this chapter.

With their nano-scaled dimensions and extremely elevated optical nonlinearity, carbon nanostructures including single-walled carbon nanotubes and graphene have played a critical role in generating ultrafast optical pulses. The pulsation relies on passive mode-locking of the nanostructures, and has been enhanced by employing an evanescent field interaction scheme that guarantees the all-fiber high-power operation. Preparation schemes for pulsating devices have been evolving via the development of elegant processes such as optical deposition, electrospray, and aerosol deposition of carbon nanostructures, ensuring the dramatic increase of process efficiency. In this chapter, details of the technical achievements are addressed.

Because of their estimated ultra-high third-order nonlinearity, single-walled carbon nanotubes (CNTs) can be regarded as a potential new material for optical nonlinearity. The nonlinearity of CNTs is believed to originate from the inter-band transitions of the π-electrons, causing nonlinear polarization. In this respect, CNTs are similar to other organic optical materials that exhibit extremely high nonlinearity. CNT-based photonics devices offer several key advantages, including ultrafast response, robustness, tunability of wavelength, and compatibility to fibers. This chapter will describe the design and fabrication of CNT-based nonlinear photonic devices. CNTs with suitable diameters – and thus suitable operational wavelengths – are deposited or grown directly on different types of fibers or waveguides to ensure effective CNT–light interaction. Optical nonlinear effects including four-wave mixing (FWM), cross-phase modulation (XPM), and self-phase modulation (SPM) have been observed experimentally using fabricated CNT-based devices. Corresponding wavelength conversion and optical signal regeneration applications based on various nonlinear effects are discussed.

Single-walled carbon nanotubes (SWCNTs) possessing outstanding linear and nonlinear optical properties are utilized as saturable absorbers (SAs) for passive mode-locking of different bulk solid-state lasers in a wide spectral range between 0.8 and 2μm. To overcome some of the limitations and drawbacks of currently available saturable absorbers, diverse carbon nanotubes and techniques for fabrication of single-walled carbon nanotube saturable absorbers (SWCNT-SAs) are investigated. In this chapter, we discuss various manufacturing procedures and essential characteristics of SWCNT-based passive mode-locking devices, and review recent demonstrations of passively mode-locked solid-state lasers employing different types of SWCNT-SAs.

Single-walled carbon nanotubes (SWCNTs) have recently attracted tremendous interest as a nanomaterial for photonics and quantum photonics devices. Here we shall review recent work with a focus on quantum light properties such as blinking and spectral diffusion, and in particular, methods and techniques to suppress these detrimental effects with the goal of enhancing optical emission. Furthermore, we shall review recent work on the generation and detection of nonclassical light emissions from individual SWCNTs embedded in polymer cavities, and discuss the role of spatial exciton localization along the tube.

This chapter discusses the background knowledge and provides a literature review of carbon-nanotubes-based metamaterials and other nanophotonic devices we present in the chapter. The materials properties of carbon nanotubes are discussed, along with their possible application in producing metamaterials which display artificial optical properties. A detailed analysis of different types of metamaterials is presented, along with their theory and applications. The utilization of silicon nanopillars for producing photonic crystals and the enhanced reflection effects are discussed. Lastly, the theoretical background and designing of carbon nanotube forests-based Fresnel lenses are presented.

This chapter describes how the semiconducting-single-wall nanotube (SWNT) extraction affects their luminescence properties and how such properties can be exploited to fabricate optical sources emitting in near-infrared wavelengths ranging from 1 to 2μm. The main applications of carbon nanotube (CNT) lasers are aimed at optical interconnects and biophotonics. We review recent achievements in obtaining optical gain in thin films doped with CNTs. Techniques for determining optical gain in CNTs are considered with particular focus on the variable strip length (VSL) method and choices to integrate nanotubes in the optical waveguide are discussed.

Carbon nanotubes (CNTs) are excellent optoelectronic materials and have been investigated for various electronic and optoelectronic device applications, such as light-emitting diodes, photodetectors and photovoltaic cells. This chapter begins with a general discussion on the various types of CNT diodes. It then focuses on a particular type of CNT diode fabricated by a doping-free process, and its application in photovoltaic cells and light-emitting diodes. The chapter ends with an outlook for the use of CNT in further integrated nanoelectronics and optoelectronics.