Comparison of reflector concepts for a 250 GHz CARM cavity

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imaging the coupling of terahertz radiation to a high electron mobility transistor in the near field

We used AlGaN/GaN high electron mobility transistors as room-temperature direct detectors of radiation at 0.15 THz from a free electron laser, hence 5 times higher than their cutoff frequency of 30 GHz. By near-field active mapping we investigated the antenna-like coupling of the radiation to the transistor channel. We formulate a model for the detection based on self-mixing in the transistor channel. The noise equivalent power is found in the range of 10^{-7} W/Hz^{0.5} without any optimization of the device responsivity. Present day AlGaN/GaN fabrication technology may provide operation at higher frequency, integration of amplifiers for improved responsivity and fast switches for multiplexing, which make the detector here described the basic element of a monolithic terahertz focal plane array

Coulping between free propagating and guided modes in a hybrid resonator for a waveguide free electron laser

Submitted to Opt. CommSIGLEITItal

Kinematic and dynamic properties of a waveguide FEL

Submitted to Opt. CommunSIGLEITItal

Waveguide tapering for FEL in the high gain regime

Submitted to Opt. CommunicationsSIGLEITItal

Towards a wave theory of charged beam propagation

Submitted to Opt. CommSIGLEITItal

TWISS parameters and evolution of quantum harmonic oscillator states

Submitted to Nuovo Cimento BSIGLEITItal