Thermal characteristic analysis of new structure in 850nm VCSEL

The traditional annular electrode structure vertical cavity surface emitting semiconductor lasers (VCESL), the operating current injected into the active region is only in the very narrow channel of the annular edge of the area, make the distribution of the device internal thermal field uneven, affecting the output characteristic of the device. In this paper, present a new type of petaline electrode structure, form a number of independent emitting hole, making the device internal thermal field even, output characteristic of the device is improved remarkably. Active region is GaAs/Al_0.3Ga_0.7As three quantum well structure growing by molecular beam epitaxy (MBE), using the gradual change structure of AlGaAs as DBR. Prepare annular electrode and petaline electrode with the same process in the same epitaxial wafer. At the same time, analyzed internal thermal field distribution of this two kinds of different electrode structure by ANSYS finite element thermal analysis software. Through the analysis and calculation, we know, the Rthjc of new petaline electrode structure is 3.78°C/W, the Rthjc of traditional annular electrode structure is 4.78°C/W, thermal characteristic and stability of new petaline electrode structure are better than traditional annular electrode structure obviously.