Self-mode-locking in erbium-doped fibre lasers with saturable polymer film absorbers containing single-wall carbon nanotubes synthesised by the arc discharge method

Nanotube–Polymer Composites for Ultrafast Photonics

“…Recently, NaCMC was used to prepare optical-quality SWNT-NaCMC SA composites through the aqueous-solvent route. [153,190] …”

“…In spite of poor environmental stability, water-soluble polymers, such as polyvinylalcohol (PVA), and cellulose derivatives, such as NaCMC, have been widely used for SAs, [94,97,124,125,147,148,150,153,186,190,194] since stable, highconcentration aqueous dispersions of pristine SWNTs can be easily prepared. From the fabrication perspective, NaCMC is more attractive, as the polymer acts both as a dispersant and host polymer.…”

Carbon Nanotube Polycarbonate Composites for Ultrafast Lasers

“…The experimental data are fitted by a sech 2 model, as predicted for soliton pulses [9] , and show a FWHM of 297 fs, which, divided by 1.54, the decorrelation factor for sech 2 pulses, gives a pulse width of 193 fs, amongst the shortest reported for SWNTs in fiber lasers. [4][5][6]8,11] The time-bandwidth product (TBP) is the product of the spectral width (in Hz) and the pulse duration (in seconds), and is an estimation of the pulse quality, [41] as it should be as close as possible to the minimum theoretical value calculated for a particular type of pulse. For our composites, the spectral bandwidth is $1.6 Â 10 12 Hz (13 nm), giving a TBP of 0.31, matching the theoretical value of 0.314 for Fourier transform limited sech 2 pulses.…”

“…[10] The use of SWNTs dispersed in a composite material has so far proven to be one of the most successful approaches to their application as saturable absorbers. [4][5][6][7][8]11] In fact, the modulation depth, which is proportional to the SWNT concentration, [3,5] can be controlled by tuning the SWNT concentration within the material, while the nonsaturable losses due to scattering from SWNT bundles can be minimized by making the bundles smaller than the device operation wavelength. [3,6] The latter can be achieved when SWNTs are dispersed in a solvent.…”

“…Moreover, it has a low glass-transition temperature (T g $ 85 8C), decomposes in air just above 200 8C, [20,21] and absorbs large amounts of moisture due to the high concentration of -OH groups along its chain. [21] Cellulose derivatives have also been used as polymer matrices for SWNTs, [11] though their hydrophilic character [21] may affect their transparency on a long-term basis due to moisture absorption. A set of new, stable, transparent polymers is thus needed for a significant step forward in the field.…”