Gain Coupled Grating Structure Optimization Based On High Linearity Laser Array

In this paper,the structure of high linear laser array in ROF optical wireless communication system is studied.This article through to the DFB semiconductor laser grating structure on the cavity in the coupling coefficient of electric field intensity and gain the distribution principle of in-depth research and analysis,and use the polyphase moving grating(MPS),pitch adjusting grating(CPM),distribution and coupling coefficient of the grating(DCC)simulation of DFB semiconductor laser grating structure optimization,and is verified by testing improves the laser array chip edge mode rejection ratio and the linear index.The innovation points and work of this paper are divided into the following parts:(1)The design optimization of the gain coupling grating structure:by using polyphase move,coupling coefficient,the combination of pitch adjustment,distribution of the grating structure optimization,the transverse distribution of the electric field intensity in the laser cavity is very uniform,at the same time gain coupling coefficient in laser cavity of vertical distribution is very uniform,greatly improve the edge of the laser mode rejection ratio,good to realize the characteristics of single mode laser array.The gain coupling grating is applied to the array of four channel lasers.The experimental results show that the threshold current is reduced to 11 mA,the output power is higher than 1 OdBm,and the edge mode rejection ratio reaches 41dB.(2)In order to improve the linear index of the laser array,the design USES the AlGaInAs strain multiquantum well material.Effectively prevent leakage of carrier under high temperature,the quantum efficiency,carrier scattering by upper state transition to the low-energy state of relaxed time,effectively reduce the laser array of Composite Second-Order distortion(CSO)and Composite Triple-Beat distortion(CTB),satisfing the linear array laser diode.Simulation and experimental test results consistently show that:the composite second order distortion for 66.3 dBc,composite beat distortion for 68.1 dBc,three times less than the required-60 dBc index,achieve high linear laser array linearization indicator of the chip.On the other hand,in order to achieve highly integrated photonic devices,based on the above AlGaInAs materials,further study of the erbium doped silicon based materials at high microwave photonic integrated silicon chip applications,as well as the realization of programmable,configurable silicon microwave photonic chip development.