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Polycrystalline Ce:YIG thin films deposited on silicon are promising material candidates for integrated nonreciprocal photonic devices. So far, the reported Faraday rotation of polycrystalline Ce:YIG thin films on silicon is much lower than that of their single crystal or epitaxial thin film counterparts, limiting the magneto-optical figure of merit, device bandwidth and fabrication tolerance. In this paper, we report the growth of Ce:YIG thin films on silicon from targets with high Ce concentration up to nominally Y 1.5 Ce 1.5 Fe 5 O 12 by pulsed laser deposition. The polycrystalline Y 1.5 Ce 1.5 Fe 5 O 12 thin film showed pure garnet phase, smooth surface roughness of 0.7 nm, a dominant Ce 3+ valence state and a bulk-like saturation magnetization of 125 emu/cm 3 at room temperature. This material shows high Faraday rotation of −6410 deg/cm at 1550 nm wavelength, exceeding that of an Y 2 Ce 1 Fe 5 O 12 epitaxial thin film on a GGG (100) substrate. However higher loss and lower figure of merit is also observed at 1550 nm wavelength compared to Y 2 Ce 1 Fe 5 O 12 thin films, possibly due to the low oxygen partial pressure during fabrication. Low deposition oxygen partial pressure is essential to enhance the Ce solubility and Ce 3+ concentration, which results in large Faraday rotation.

A vertical viewing 0.65 THz Solid-state Source Interferometer (SSI) has been installed for line-integrated density measurements on Experimental Advanced Superconducting Tokamak (EAST) . The SSI utilizes two independent solid-state diode sources with 2 mW output power and a base frequency multiplier, which provides a wide range of Intermediate Frequencies (IF) . The high time resolution of 0.1 μs at a 10 MHz IF has been successfully achieved. The IF signal remains almost constant for several hours without any active frequency stabilization. A sensitivity in the integrated density of 0.77× 1016 m−2 has been obtained. The density measurement has been implemented with IF ~ 0.85 MHz, in a plasma with Ip=600 kA and PLHW=2.1 MW on EAST . The line-averaged density, 3.5× 1019 m−3, measured by the SSI shows good agreement with the results measured by the HCN interferometer system and the POlarimeter-INTerferometer (POINT) system in the same discharge.

A compact terahertz continuous wave (CW) discharge-pumped Hydrogen cyanide (HCN) dual laser has been developed for better signal to noise ratio and higher time resolution, with active power and intermediate frequency (IF) control. The output power of about 1~10 mW on the 0.89 THz line has been obtained with 1 m long and 50 mm inner diameter dual discharge-pumped wave-guides laser. An output-power and IF feedback control system is applied to the HCN dual laser for output power and IF stability. This feedback system consists of two stepping motors, a piezoelectric ceramics (PZT), a PLC, a supervisory computer and the corresponding control program. The whole feedback control system can successful in stabilizing the power of the laser around 1~10 mW and the IF at around 1MHz in several hours.

An outdoor solid-state amplifier chain consists of two separate units, amplifier and power supply, and this amplifier is core of the chain. Tough environment, high heat consumption and complicated EMC requirement are the main difficulties in the structure design. Cold plate, sealed and shielded package are used to solve all these problems, which are proved to be effective by both calculation and tests.

Z-type hexaferrite (Ba 3 (Co 0.4 Zn 0.6 ) 2 Fe 23.4 O 41 ) with BST(Ba 0.5 Sr 0.5 TiO 3 ) additive was prepared by conventional solid-state reaction method. We have investigated the effects of BST additive on the complex permeability, permittivity and microwave absorption in the range of 1 MHz–1 GHz. The results from XRD and SEM indicate that as the amount of BST increases, the major phase changes to Z-phase, simultaneously M-phase and perovskite phase appear, and grain size increases. When the weight percent of BST additive in Z-type hexaferrite varied from 0% to 1.5%, the BST additive not only improved complex permeability and complex permittivity, but also provided broadband reflectivity characteristics. Meanwhile the minimum reflection point shifts to lower frequency with increase of BST content.

The metal flow in the extrusion of a pipe through a porthole-die has been analyzed experimentally, regarding the process as a combination of multi-hole die and multi-billet extrusions. The distorted grid patterns on some symmetrical planes of metal flow were observed continuously using a split-tool assembly and split specimens having square grids inscribed on their surfaces, the distribution of particle velocity being determined from the grid distortion observed. In the so-called welding plane, a symmetrical plane of metal flow, the region where welding occurs is actually located near to the die exit and occupies only a small area. To inspect the reliability of simulation results, the extrusion of A1050 pipe through a porthole-die was carried out, metal flow in the container and in the welding chamber being investigated by macro etching.

The deformation behavior in the extrusion of pipes through a porthole die has been analyzed by means of the upper-bound approach (UBA) and the results compared with experimental ones. The proposed model has a smooth boundary to the plastic region and a continuous velocity field. The predicted extrusion loads were found to be less than 10% greater than the experimentally recorded loads. The results of the analysis show that there exists an optimum depth of the welding chamber with regard to the extrusion pressure. The analysis suggests also that the pressure is greater with a larger ratio of the diameter of the welding chamber to that of the container, and that the variation tendency of the pressure with the number of portholes is effected by whether the circumcircle of portholes is fixed or not. When the length of the billet remaining in the container is smaller than the radius of the container, the plastic region extends over the whole of the billet. For the distribution of the flow velocity and the shape and volume of the dead-metal zone, there exist some differences between the predicted and the experimental results.