Terahertz field detector based on electron emission

This paper reports the electric field induced electron emission across the capacitive gap in a metamaterial structure under intense terahertz (THz) pulses. The gold metamaterial fabricated on a silicon nitride thin film can enhance the electric field greatly around the resonance frequency, resulting in THz field induced electron emission across the capacitive gap in the metamaterial structure when the incident electric field is > 60kV/cm. The emission current is measured experimentally and shows dependency on the strength of the incident field strength, which can be used as a THz detector.