Distributed Feedback Lasers Use For The Silicon-based Photonic Integrated Circuits

Along with the increasing demand of information in our society,traditional communication technologies cannot satisfy the practice requirement,fibre optical communication is more widely used to improve the speed and capacity of information.Photonic integrated circuit is the core component of the fibre optical communication system.Slicon-based photonic integrated circuit is low cost,high integration,since it can use a lot of experimental processes in the integrated circuits.Silicon-based photonic integrated circuit is very favorable for industrialization.The biggest obstacle for the industrialization of silicon-based photonic integrated circuit is the lack of light source.The research of this dissertation focuses on the light source which can be used in the silicon-based photonic integrated circuit.The main content of this dissertation is depicted as follows:Graphene Bragg gratings have been introduced to the bonding interface of the hybrid laser.Utilizing the optical absorption of the graphene Bragg gratings,a hybrid distributed feedback(DFB)laser based on graphene Bragg gratings has been established.The theory calculation shows that the single mode at Bragg wavelength can be selected under different gains and cavity lengths.The hybrid DFB laser based on graphene Bragg gratings is insensitive to the facet reflectivities and facet phases,as compare to the index-coupled hybrid DFB lasers.The side-mode suppression ability of this device is also higher than the traditional hybrid DFB lasers.This laser has a high single mode yield.The buried heterojunction laser is bonded to a SOI waveguide with a single layer of graphene Bragg gratings placed at the bonding interface by selective-area metal bonding,a hybrid DFB laser based on the single layer graphene Bragg gratings has been fabricated.The laser can realize continuous-wave operation at room temperature,the threshold current is 48 mA,the maximum output power from a single facet is 0.33 mW.The device achieves single-mode oscillation throughout various injection levels,the side-mode suppression ratio(SMSR)of the laser is higher than 48 dB.This device also has a very low thermal impedance,= 81.5 ?/W.A hybrid DFB laser based on double-layer graphene Bragg gratings is fabricated.The laser can realize continuous-wave operation at room temperature,the threshold current is 38 mA,the maximum output power from a single facet is 0.11 mW.As compared to the hybrid DFB laser based on single layer graphene Bragg gratings,the maximum output power is reduced by 0.22 mW.The device achieves single-mode oscillation under different injection levels.The laser exhibits a lasing peak at 1538.5 nm and a SMSR of 47.8 dB at 150 mA.High power 1.3 ?m DFB laser which can be used for the paralell single mode 4 lanes(PSM4)silicon-based photonic integrated circuit has been designed and fabricated.Under consideration of the carrier leak,free carrier absorption,grating coupling coefficient,the thickness,doping level of the separated confinement heterostructure and grating layer are optimized through the simulation.The structure of the high power 1.3 ?m DFB laser has been established.Based on these simulation results,we fabricated the high power 1.3 ?m DFB laser,the laser can realize continuous-wave operation at room temperature,the maximum output power from a single facet is 63.5 mW and the SMSR is 50 dB.