Terahertz generation from Si_(3)N_(4) covered photoconductive dipole antenna

We observe enhanced terahertz (THz) radiation generated from a Si_(3)N_(4) film-coated GaAs photoconductive dipole antenna. Compared to an uncoated antenna with identical electrode geometry and optical excitation power, the Si_(3)N_(4) film-coated antenna has a higher effective DC resistance and larger breakdown voltage. As a result, the peak amplitude of generated THz radiation is significantly enhanced due to the Si_(3)N_(4) film-coated layer.