Mode-locked soliton pulse generation using copper phthalocyanine absorber in long erbium-doped fibre laser cavity

We present the development of a mode-locked erbium-doped fibre laser (EDFL) utilizing Copper Phthalocyanine (CuPc) as a saturable absorber (SA). CuPc exhibits unique optical properties, including its high nonlinear optical response and rapid recovery time. To seamlessly integrate CuPc into the laser cavity, we employed a simple embedding technique within a polymer film. The SA demonstrates a modulation depth of 3.1% and a saturation intensity of 17 MW/cm(2). Operating within a pump power range of 90.6 to 122.9 mW, the laser achieves mode-locked operation, producing a soliton pulse train with a fundamental frequency of 1.82 MHz and a pulse width of 6.4 ps at a wavelength of 1561.5 nm. It attains a maximum output power of 13.97 mW and a pulse energy of 7.67 nJ. These results underscore CuPc's potential as a promising material for generating mode-locked pulses, suggesting new avenues in ultrafast laser development for diverse applications.