1.55-μm InGaAsP-InP two-section DFB lasers with varied ridge width, both gain-coupled and index-coupled, have been fabricated. Self-pulsations with frequencies around 40 GHz are observed. The related mechanism and the tunability of generated self-pulsations is studied.
By employing 2D plane wave expansion (PWE) and finite difference time domain (FDTD) methods,a photonic crystal waveguide (PCW) based on the compound square lattice structure is presented. Band-gap can be observed for TM polarization and compared with the simple lattice structure based on the same material,the band-gap is increased by 62.7%. Byoptimizing the parameters we get the PCW with the propagation only near the wavelength of 1.55 μm and a flat group indexcurve in a wide wavelength range of 40 nm. And the group velocity dispersion compensation can be realized by thestructure optimization. The results provide a reference for the study and application of photonic crystal waveguide based on the compound lattice structure.
This paper presents a novel scheme to monolithically integrate an evanescently-coupled uni-travelling carrier photodiode with a planar short multimode waveguide structure and a large optical cavity electroabsorption modulator based on a multimode waveguide structure. By simulation, both electroabsorption modulator and photodiode show excellent optical performances. The device can be fabricated with conventional photolithography, reactive ion etching, and chemical wet etching.
A 1.55μm InGaAsP-InP three-section DFB laser with hybrid grating is fabricated and self-pulsations （SP） with frequencies around 20GHz are observed. The mechanism of SP generation in this device is researched. Furthermore,the important role of the phase tuning section on the SP is investigated.
