Magnetic field dependence of terahertz emission from an optically excited GaAs p-i-n diode -: art. no. 085307

The magnetic field dependence of the coherent tetrahertz radiation emitted by a GaAs p-i-n diode excited by femtosecond optical pulses has been investigated in the limits that the cyclotron frequency is greater than and smaller than the scattering rate. The variation in emitted power with magnetic field in different polarizations and geometries is in good agreement with the predictions of a simple, quantitative Drude-Lorentz transport model taking into account the radiative properties of electric dipoles at a dielectric interface and the effects of screening and source size. Absolute power measurements are also in agreement with a simpler model based on discharge of the sample capacitance.