Low-Resistance, High-Power-Efficiency Vertical Cavity Microlasers

摘要

The purpose of this project was to improve the total power efficiency of verticalcavity microlasers to further the commercialization of large arrays of semiconductor lasers integrated on single chips. Vertical cavity surface emitting lasers are tiny semiconductor lasers, typically about 10 micrometers in diameter, whose optical cavities and electrical injection schemes are radically different from conventional edge emitting semiconductor lasers. The VCSSEL geometry emits high quality beams perpendicular to the face of the chip, rather than out the edge of the chip, and can be readily fabricated in one and two dimensional arrays. A preliminary demonstration of the modulation doped approach was made. The result was a record low threshold voltage of 1.7 volts for VCSELs. Previously, VCSELs required a minimum of about 2.5 volts for thresholed or had very high current thresholds. This demonstration destroyed the then widely held micsconception that VCSELs inherently were high resistance and high voltage devices.