Finely Engineered Wideband Low-Dispersion Slow Light Photonic Crystal Waveguides For Higher-order Temporal Solitons Compression

With the CMOS compatible characteristics and extraordinary nonlinear enhanced effects,the silicon photonic crystal waveguides(Si-PhC-wgs)with their unique slow light characteristics have been widely studied recently,which highlight the future of the silicon photonics applications in on-chip optical integration,optical interconnect and optical computing.Ultra-short laser pulses and solitons pulse compression are significant for exploiting the potential of the Si-PhC-wgs used in nonlinear optics and optical communication.However,the dispersion of the ordinary photonic crystal waveguides is usually at a high level,which will almost ruin all the nonlinear enhanced advantages of this new waveguide.Then it is urgently needed for dispersion engineering for low-dispersion waveguides,especially for the ultra-short laser pulses,where the low-dispersion characteristics must maintain within a wide bandwidth.In this thesis,two novel finely engineered slow light Si-PhC-wgs are designed for higher-order temporal solitons compression,and the ultra-short pulses' evolution in these novel waveguides are demonstrated by numerical simulations.The main points are as follows:1.By orthogonally dual-shifting the air-hole rows in the triangular photonic crystal waveguide,we obtain a novel finely engineered slow light Si-PhC-wgs within a wide wavelength range with only low anomalous dispersion covering.And the simulation results of the picosecond pulses' evolution are based on nonlinear Schr?dinger equation(NLSE)modeling,which demonstrate that the input picosecond pulses in the broad wavelength range with ultra-low pJ pulse energy can be stably compressed by a factor of 6 to higher-order temporal solitons in a 250?m short waveguide.2.We designed a novel slow-light silicon photonic crystal waveguide which can operate over an extremely wide flatband for femtosecond pulses compression.By neatly tuning the radius and positions of the second air-holes rows,an extremely wide flat slowlight band about 35 nm is achieved for the photonic crystal waveguides,which will firstly match the urgent requirement for governing and controlling the femtosecond pulses in slow-light photonic crystal waveguides.We demonstrate the solitons compression of a 200 fs pulse within a 100?m waveguide by numerical simulations.In summary,two novel slow light Si-PhCWs with extremely wide flatband and low dispersion has been proposed.And we demonstrate its potential applications in ultra-short pulses silitons compression,the results will benefit the ultra-short pulses operations in the next generation on-chip optical systems.