Optimizing Single‐Walled‐Carbon‐Nanotube‐Based Saturable Absorbers for Ultrafast Lasers

Abstract

The application of single-walled carbon nanotubes (SWCNTs) as saturable absorbers (SA) in a Nd:glass femtosecond laser is verifi ed as a promising alternative to traditional semiconductor saturable-absorber mirrors (SESAMs). The shortest laser pulses achieved with a SWCNT-SA fabricated by the slow-evaporation method are reported herein. Nearly Fourier-limited 288 fs pulses are obtained with negative-dispersion soliton mode-locking. The importance of the properties of the starting material, such as the degree of purity and the chirality, and the successive slow-evaporation deposition method is proven by using a multitechnique approach based on X-ray diffractometry, scanning electron microscopy, and μ -Raman spectroscopy. The high degree of nanotube alignment on the glass substrate and also the slight metallic character due to electron transfer between the glass matrix and the nanotubes themselves are identifi ed as the main features responsible for the good laser response.

Nonlinear absorption of SWNT film and its effects to the operation state of pulsed fiber laser

“…Figure 1(a) shows the Raman spectrum of SWNT/PVA film. Different parameters such as diameter, electrical characteristic, direction, and chirality can be derived from the main firstand second-order Raman modes of the Raman spectrum [30]. Radial-breathing-mode (RBM) band (100-400 cm −1 ) is induced from radial vibration of the carbon tube in phase, which can also be utilized to estimate the diameter of the tube.…”

Functional Porous MOF-Derived CuO Octahedra for Harmonic Soliton Molecule Pulses Generation

“…People have theoretically explored and revealed the mechanism of the formation of a variety of ultrashort pulse phenomena. , In recent years, the generation of ultrashort laser pulses based on the interaction of nano- or microstructured materials and lasers as well as the exploration of the materials’ nonlinear optical properties, are new research hotspots in the world. At present, allotropes of carbon such as graphene, carbon nanotubes, and graphdiyne have been successively used to generate ultrashort laser pulses. − Among them, Chernysheva et al have made a detailed review of different doped fiber lasers with CNTs as SAs. Other materials, like black phosphorus, MXene, transition metal dichalcogenides (TMD), topological insulators (TI) and bismuthene etc.…”

Thermal analysis for laser selective removal of metallic single-walled carbon nanotubes

“…Figure 1 schematically shows such a scheme using laser radiation to remove m-SWNTs based on the fact that m-SWNTs absorb much more energy and can be destroyed in air in preference to their semiconducting counterparts when wavelength of radiation is appropriate. [15][16][17][18][19][20][21][22][23][24] This process begins with the growth of perfectly aligned SWNTs on a quartz substrate as shown in Fig. 1(a).…”

“…1(b). Although the concept of ablation has been demonstrated under some conditions, [15][16][17][18][19][20][21][22][23][24] analytical modeling is needed to help the design of experiments to explore further possibilities.…”