Fabrication, characterization and mode locking application of single-walled carbon nanotube/polymer composite saturable absorbers

Abstract

We present the fabrication of a high optical quality single-walled carbon nanotubes (SWNTs) polyvinyl alcohol (PVA) composite film. The composites demonstrate strong saturable absorption at ∼1.5 μm, the spectral range for optical communications. By measuring the nonlinear transmission of a sub-picosecond pump pulse through the film, we were able to deduce a saturation fluence of ∼13.9 μJ/cm 2 and a modulation depth ∼16.9% (in absorption) at a high pulse fluence ∼200 μJ/cm 2 . Transient saturable absorption is investigated by measuring the transmitted autocorrelation traces at various incident power levels. Observed side-peak suppression indicates a fast recovery time on the scale of ∼1 ps for our saturable absorber devices. Furthermore, we use these SWNT-PVA composite saturable absorbers as mode-lockers in an Er 3+ fiber ring laser and achieve ∼560 fs pulse generation with good jitter performance and long term stability. The laser performance is also associated with the parameters of our SWNT based saturable absorber.

High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber

“…The fabrication procedure of our nanotube based polymer composite is similar to the previous reports 54 64 65 66 . The single wall carbon nanotube (SWCNT) is produced using a laser ablation technique.…”

Ceramic matrix composites containing carbon nanotubes

“…On the other hand, nanotube arrays and composites have been successfully used as saturable absorbers for mode-locked lasers 150,151 . In high power situations, inorganic matrices may offer improved stability than current systems.…”

Hybrid mode-locked erbium-doped all-fiber soliton laser with a distributed polarizer

“…To initiate and sustain USP generation in the ring laser cavity, saturable absorbers based on carbon nanostructures, such as single-walled carbon nanotubes (SWCNTs) [5][6][7][8][9] or graphene [9,10], are the most suitable. Compared to SESAMs, SWCNTs benefit from much easier fabrication techniques, the possibility of being used in both linear and ring cavities, and fast recovery time of less than 500 fs [11].…”

“…Compared to SESAMs, SWCNTs benefit from much easier fabrication techniques, the possibility of being used in both linear and ring cavities, and fast recovery time of less than 500 fs [11]. Furthermore, SWCNTs can be naturally dispersed in different polymer matrices, leading to the fabrication of high optical quality films that can be further incorporated into the laser cavity without breaking the allfiber setup as well as requiring mechanical or thermal adjustments [5][6][7][8][9]. Unlike SESAMs, SWCNTs exhibit saturable absorption over a much wider spectral band (up to 500 nm and more) due to the inherent distribution of SWCNTs diameters [5][6][7][8][9], which can be quite useful for laser applications.…”