Extrinsic frequency response of a wide-bandwidth metal semiconductor metal diode

The active area of an interdigitated GaAs MSM diode with 1-μm finger width and spacing is extended with two novel structures, one an integrated tapered coplanar waveguide and another coplanar stripline transmission line. The diodes were illuminated by 5-ps laser pulses of 30-μm in diameter, and the external overall frequency response of the complete system, found by taking the Fourier transform of the detected temporal signal was 2.4 GHz for the coplanar waveguide and 1.4 GHz for the stripline geometry.