High THz Average Power Generation from Photoconductive Connected Array Antenna Excited by High-Power Laser

Abstract

We report on high power THz emission from LT-GaAs photoconductive emitters, excited with a frequency-doubled, high power ultrafast Yb laser emitting 100 fs pulses at 515 nm (green) at a high repetition rate of 91 MHz. The device presented in this work incorporates a dedicated connected array. First, we describe the general methodology for designing such impedance matched photoconductive connected array devices, then we describe how this methodology was applied for the design of a 361-element photoconductive connected array specifically optimized for the high optical power (20 W) at 515 nm laser wavelength and 91 MHz repetition rate. The combination of these optimized devices and high power laser at very high repetition rate allow us to demonstrate a high THz power of 10.1 mW during the on-cycle of a chopper with 50% duty cycle.