An Improved Design for an All-Optical Flip-Flop Based on a Nonlinear 3-Sections DFB Laser Cavity

作     者：Hossam Zoweil Hossam Zoweil

作者机构：City of Scientific Research and Technology Applications Advanced Technology and New Materials Research Institute Alexandria Egypt 

出 版 物：《Optics and Photonics Journal》 (光学与光子学期刊（英文）)

年 卷 期：2016年第6卷第5期

页      面：87-100页

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0803[工学-光学工程] 

主　　题：All-Optical Flip-Flop Distributed Feedback Laser Nonlinearity Switching 

摘      要：A new all optical flip-flop based on a 3-sections nonlinear semiconductor DFB laser structure is proposed and simulated. The operation of the device does not require a holding beam. Electrical current injection into an active layer provides optical gain to the laser mode. The wave-guiding layer consists of a linear grating section centered between 2 detuned nonlinear grating sections. The average refractive index in the nonlinear sections is slightly higher than the refractive index of the middle section. A negative nonlinear refractive index coefficient exists along the nonlinear sections. In the “OFF state, the DFB structure does not provide enough optical feedback to lase due to the detuned sections. At high light intensity in structure, “ON state, detuning decreases and the DFB structure allows for a laser mode that sustains the decrease in detuning to exist. The nonlinearity is provided by direct photon absorption at the Urbach tail. Numerical simulations using GPGPU computing show nanoseconds transition times between “OFF and “ON states.