Structure Optimization And Characteristc Simulaton Of Single-mode High Power Verical Cavity Surface Emitting Laser

The vertical-cavity surface-emitting laser(VCSEL)has emerged as an attractive low-cost,high speed and low consumption light source,and this kind of laser has many superior characteristics with the traditional Edge-Emitting Laser,including: low-threshold current,high power,circular and low divergence output beams,testability at the wafer level,addressable two dimensional array integration,and so on.It has been extensively used in the higher data rate communication,optical storage,optical information processing and so on.Owing to the extremely short cavity,longitudinal single mode operation is inherent to the VCSEL structure.Unfortunately,due to its relatively large transverse dimensions,several transverse modes are supported.For a typical oxide confined VCSEL,the device cannot achieve single mode operation when its aperture larger than 5?m,which limits output power.Surface relief structure and High Contrast Subwavelength Gratings(HCG)structure are two methods to achieve high power single mode VCSEL.Through etching a certain depth on the surface of upper Distributed Bragg reflector(DBR)of VCSEL,the loss of some modes can be increased.Thus the single-mode can achieve through mode selection.In this paper,an inverted surface relief vertical-cavity surface-emitting laser(ISR-VCSEL)with annular light emitting window have been presented and investigated.The most prominent structural feature of the device is that stable single-higher-order transverse mode emission is supported.Then we research 2?m HCG-VCSEL.The HCG structure replace conventional DBR to form a new optical resonator,due to the HCG structure have advantages of high refractive index contrast and mode discriminant to achieve fundamental transverse mode emission.The main parts of the thesis are as follows:1 Investigated surface-relief VCSEL with ring-shaped emitting region,the results show that single higher-order mode at room temperature with a maximum output power of 15.2 m W,accounting for 84% of the total power;beam divergence angle is less than 4.5°.The near-filed supports single higher-order mode lasing;the structure has excellent temperature stability,at the temperature of 450 K,there is still a certain output power.The performance is more stable than the similar devices.2 Fabrication and text the SR-VCSEL,the maximum power is 9.8m W,SMSR is larger than 25 d B,even if the driving current is 2 times of the threshold current,and the out power is 4m W even at high temperature of 360 K.The device has excellent temperature stability of both output power and optical mode.3 Investigated 2?m HCG-VCSEL,the simulation results show,the active gain region is placed at antiwave guide node,meeting with the maximum light,reaching the maximum gain of the model,The fundamental transverse mode lasing is achieved under the large aperture of the n++In As/p++Ga Sb tunnel junction with a diameter of 30?m.The device has excellent single mode characteristics,the lasing spectrum is 1.99945?m,FWHM is about 0.05 nm,threshold current is 1.8m A,the maximum power is 9.8m W @15m A,threshold voltage is 0.5V,and the differential series resistance is about 100 ohms,less than the resistance of the same type of device.