Terahertz Radiation Generation by Laser Interaction with a Periodic Array of GaAs Structure

Abstract

In the current study, a method for generating terahertz (THz) radiation using a GaAs structure array and transient current from a laser is proposed. The current generated across the length of these structures is responsible for the generation of THz radiation, where the entire system acts as phase-array dipole antennae. The maximum emitted THz power is achieved in the directions, where the conditions −bd/𝑐 𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜙=𝑝1𝜋 and −bd/𝑐 𝑠𝑖𝑛𝜃=𝑝2𝜋 are met; b and d are the widths and the length of a single GaAs structure and p1 and p2 are the integers. Where M1 and M2 are the numbers of GaAs structures along the longitudinal and transverse directions of the laser propagation, respectively, the overall antenna gain is observed to be M12 M22in these directions. The antennae approach used for the proposed GaAs periodic array enables us to obtain the THz profile in the frequency domain and realize the role of arrays and size of GaAs structure, making the emitted radiation suitable for its THz Time Domain Spectroscopic applications.