Investigation of Bias-Voltage Dependence of Radiation Power in Bi-2212 Intrinsic Josephson Junction THz-Wave Oscillators

Bias-voltage dependence of the radiation power of a THz-wave oscillator using Bi-based cuprate intrinsic Josephson junctions was investigated. A rectangular mesa with 80 × 300 × 2 μm³ was fabricated from a single crystal of the cuprate. The maximum power of 25 μW at a frequency of 0.514 THz was obtained by a bidirectional sweep in an I-V curve of the mesa. The power was two times higher than that obtained by a unidirectional sweep. The experimental result is qualitatively consistent with that of numerical simulation using the coupled sine-Gordon equation with the radiation boundary condition.