The polarization of traditional photonic crystal（PC） vertical cavity surface emitting laser（VCSEL） is uncontrollable,resulting in the bit error increasing easily.Elliptical hole photonic crystal can control the tr...The polarization of traditional photonic crystal（PC） vertical cavity surface emitting laser（VCSEL） is uncontrollable,resulting in the bit error increasing easily.Elliptical hole photonic crystal can control the transverse mode and polarization of VCSEL efficiently.We analyze the far field divergence angle,and birefringence of elliptical hole PC VCSEL.When the ratio of minor axis to major axis b/a = 0.7,the PC VCSEL can obtain single mode and polarization.According to the simulation results,we fabricate the device successfully.The output power is 1.7 mW,the far field divergence angle is less than 10°,and the side mode suppression ratio is over 30 dB.The output power in the Y direction is 20 times that in the X direction.展开更多
According to the requirements, an active infrared system is designed, which is composed of the emitting and receiving parts. The emitting part consists of a GaAs semiconductor laser device and binoculars optical syste...According to the requirements, an active infrared system is designed, which is composed of the emitting and receiving parts. The emitting part consists of a GaAs semiconductor laser device and binoculars optical system. A Si photodiode is selected as the receiving device, and a preamplifier circuit is designed to match the detector and further improve the signal to noise ratio. The laser encoding mode is utilized to enhance the anti disturbance. The theoretical analysis of this system is presented and a system prototype is made according to the requirement. The experimental results agree well with the theoretical prediction.展开更多
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2008AA03Z402)the Beijing Municipal Natural Science Foundation,China (Grant Nos. 4092007,4112006,4102003,and 4132006)+1 种基金the National Natural Science Foundation of China (Grant Nos. 61076044,61036002,61036009,and 60978067)the Doctoral Fund of the Ministry of Education of China (Grant No. 20121103110018)
文摘The polarization of traditional photonic crystal（PC） vertical cavity surface emitting laser（VCSEL） is uncontrollable,resulting in the bit error increasing easily.Elliptical hole photonic crystal can control the transverse mode and polarization of VCSEL efficiently.We analyze the far field divergence angle,and birefringence of elliptical hole PC VCSEL.When the ratio of minor axis to major axis b/a = 0.7,the PC VCSEL can obtain single mode and polarization.According to the simulation results,we fabricate the device successfully.The output power is 1.7 mW,the far field divergence angle is less than 10°,and the side mode suppression ratio is over 30 dB.The output power in the Y direction is 20 times that in the X direction.
文摘According to the requirements, an active infrared system is designed, which is composed of the emitting and receiving parts. The emitting part consists of a GaAs semiconductor laser device and binoculars optical system. A Si photodiode is selected as the receiving device, and a preamplifier circuit is designed to match the detector and further improve the signal to noise ratio. The laser encoding mode is utilized to enhance the anti disturbance. The theoretical analysis of this system is presented and a system prototype is made according to the requirement. The experimental results agree well with the theoretical prediction.
