Improved performance of GaAs-based terahertz emitters

We have improved the stability and performance of terahertz photoconductive (Auston) switches using a combination of (NH<inf>4</inf>)<inf>2</inf>S surface passivation and silicon nitride (Si<inf>3</inf>N<inf>4</inf>) encapsulation. The passivation and encapsulation processes increased the average terahertz power generated four-fold.