Abstract
To calculate the radiation properties of terahertz-wave oscillators using intrinsic Josephson junctions, an analytical solution of the coupled sine-Gordon equation was obtained by applying continuous approximation and a radiation boundary condition in a 3D model for the oscillator mesa. The I-V characteristics, electromagnetic field distributions and bias dependence of radiation power were obtained by the analytical solution. These properties agree well with experimental results obtained from the oscillator fabricated from a Bi2Sr2CaCu2O8+δrectangular mesa with 78 μm wide, 138 μm long and 1.1 μm high. The analytical formulae are useful for designing the oscillator using the intrinsic Josephson junctions for practical applications.