High power generation of THz from 1550-nm photoconductive emitters.

Two photoconductive emitters - one with a self-complementary square spiral antenna, and the other with a resonant slot antenna - were fabricated on a GaAs epilayer embedded with ErAs quantum dots. Driven with 1550 nm mode-locked lasers, ~117 µW broadband THz power was generated from the device with the spiral antenna, and ~1.2 µW from the device with resonant slot antenna. The optical-to-THz conversion is through extrinsic photoconductivity.