The paper introduces a family of three-DOFs translational-rotational Parallel-Kinematics Mechanisms (PKMs) as well as the mobility analysis of such family using Lie-group theory. Each member of this family has two-rotational one-translational DOFs. A novel mechanism is presented and analyzed as a representative of that family. The use and the practical value of that modular mechanism are emphasized.

We have designed, fabricated and tested resonant cavity enhanced visible-blind AlGaN-based Schottky photodiodes. The bottom mirror of the resonant cavity was formed with a 20 pair AlN/Al0.2Ga0.8N Bragg mirror. The devices were fabricated using a microwave compatible fabrication process. Au and indium-tin-oxide (ITO) thin films were used for Schottky contact formation. ITO and Au-Schottky devices exhibited resonant peaks with 0.153 A/W and 0.046 A/W responsivity values at 337 nm and 350 nm respectively. Temporal high-speed measurements at 357 nm resulted in fast pulse responses with pulse widths as short as 77 ps. The fastest UV detector had a 3-dB bandwidth of 780 MHz.

High-performance solar-blind AlGaN-based Schottky photodiodes have been demonstrated. The detectors were fabricated on MOCVD-grown AlGaN/GaN hetero-structures using a microwave-compatible fabrication process. Current-voltage, spectral responsivity, noise, and high-speed characteristics of the detectors were measured and analyzed. Dark currents lower than 1 pA at bias voltages as high as 30 V were obtained. True solar-blind detection was achieved with a cut-off wavelength lower than 266 nm. A peak device responsivity of 78 mA/W at 250 nm was measured under 15 V reverse bias. A visible rejection of more than 4 orders of magnitude was observed. The solar-blind photodiodes exhibited noise densities below the measurement setup noise floor of 3×10−29 A2/Hz around 10 KHz. High-speed measurements at the solar-blind wavelength of 267 nm resulted in 3-dB bandwidths as high as 870 MHz.