Carbon nano-material based saturable absorbers and their application to mode-locked lasers

The first part of this thesis presents the implementation of a passively mode-locked fiber ring laser incorporating single walled carbon nanotubes (SWNT). The laser was found to generate soliton pulses with pulsewidths on the order of 1 ps and bandwidths of 3.5 nm at a repetition rate of 10 MHz. Power dependent harmonic mode-locking was demonstrated, generating pulses with a repetition rate of up to 130 MHz. The second part of the thesis presents an attempt to determine if carbon nanoparticles, known as carbon black, exhibit similar nonlinear optical properties to other forms of carbon nano-materials, making them suitable for use in mode-locked lasers. The nonlinear measurements were inconclusive, however a Q-switched laser was demonstrated incorporating carbon black. The laser had power dependent pulsewidths on the order of 10 us, repetition rates on the order of 27 kHz and was wavelength tuneable in the region of 1545 to 1565 nm.Mode-locked lasers are ideally suited to generate ultrashort and high power laser pulses which have found uses in many fields. Passively mode-locked lasers require a nonlinear optical component known as a saturable absorber. Recently, carbon nano-materials, specifically carbon nanotubes and graphene have been shown to be promising saturable absorber materials around which passively mode-locked lasers can be implemented. The first part of this thesis presents an attempt to determine if carbon nanoparticles, known as carbon black, exhibit similar nonlinear optical properties to other forms of carbon nano-materials, making them suitable for use in mode-locked lasers. The second part of the thesis details the implementation of a fiber ring laser mode-locked with single walled carbon nanotubes (SWNT). The laser is characterised in the both the time and frequency domains under different intracavity power, and the various modes of operation are analysed