An analytical model is proposed for an optically controlled Metal Semiconductor Field Effect Transistor (MESFET), known as Optical Field Effect Transistor (OPFET) considering the diffusion fabrication process. The electrical parameters such as threshold voltage, drain-source current, gate capacitances and switching response have been determined for the dark and various illuminated conditions. The Photovoltaic effect due to photogenerated carriers under illumination is shown to modulate the channel cross-section, which in turn significantly changes the threshold voltage, drainsource current, the gate capacitances and the device switching speed. The threshold voltage V T is reduced under optical illumination condition, which leads the device to change the device property from enhancement mode to depletion mode depending on photon impurity flux density. The resulting I-V characteristics show that the drain-source current IDS for different gate-source voltage V gs is significantly increased with optical illumination for photon flux densities of Φ = 10 15 and 10 17 /cm 2 s compared to the dark condition. Further more, the drain-source current as a function of drain-source voltage V DS is evaluated to find the I-V characteristics for various pinch-off voltages V P for optimization of impurity flux density Q Diff by diffusion process. The resulting I-V characteristics also show that the diffusion process introduces less process-induced damage compared to ion implantation, which suffers from current reduction due to a large number of defects introduced by the

Mitsubishi Heavy Industries, Ltd. (MHI) Group has been developing additive manufacturing (AM) as a method that can manufacture parts with complex shapes and considering its application to manufacturing processes. In combustor components, application of AM process to rapid prototyping and multi-cluster nozzles for hydrogen or ammonia gas fuel is being considered. In turbine parts, with the aim of improving performance by reducing the amount of cooling air, the adoption of a complex internal cooling structure, which cannot be made with conventional manufacturing methods but can only be made by AM, is being considered. This paper describes design for AM technology for gas turbine components and metal AM process technology such as building simulation based high stiffness support design and pre-set distortion, microstructure control by laser scanning conditions, quality control through in-process monitoring tools and application of AM technology to gas Turbine Components.