Terahertz P-I-N Modulator

Theoretical and experimental research of silicon surface oriented integrated p-i-n-structures as quasi-optical modulators of terahertz frequency range have been done. The problem of double injection into i-region has been numerically solved. A possible role of nonlinearity in boundary conditions at injecting junctions is pointed out. Our simulations demonstrate that an effective modulation of terahertz wave beams by Si p-i-n-structures can be achieved up till the frequencies 2-2.5 THz. Measurements at 400 GHz confirm the results of simulations. The possibility of modulation of picosecond monopulses is also investigated. The investigation of modulator includes the analysis of the nonlinear losses, which are very important in sub millimeter waves. The field value of the nonlinear effects domination is obtained.