Ultra-high speed (270 GHz) near-ballistic uni-traveling-carrier photodiode with very-high saturation current (17 mA) under a 50 Ω load

Author(s):  
J.-W. Shi ◽  
F.-M. Kuo ◽  
Mark Rodwell ◽  
J. E. Bowers
Author(s):  
Roman V. Kazban ◽  
James J. Mason

Even though many models for machining exist, most of them are for low-speed machining, where momentum is negligible and material behavior is well approximated by quasi-static plastic constitutive laws. In machining at high speeds, momentum can be important and the strain rate can be exceedingly high. For these reasons, a fluid mechanics approach to understanding high-speed, very high-speed, and ultra-high-speed machining is attempted here. Namely, a potential flow solution is used to model the behavior of the material around a sharp tool tip during machining at high speeds. It is carefully argued that the potential flow solution is relevant and can be used as a first approximation to model the behavior of a metal during high-speed, very high-speed, or ultra-high-speed machining events; and at a minimum, the potential flow solution is qualitatively useful in understanding mechanics of machining at high speeds and above. Interestingly, the flow solution predicts that there is a stagnation point on the rake face, not at the tool tip as is usually assumed. Because the stagnation point is not at the tool tip, the flow solution predicts a significant amount of deformation in the workpiece resulting in large residual strains that may lead to a temperature rise on the finished surface.


1973 ◽  
Vol 187 (1) ◽  
pp. 625-634 ◽  
Author(s):  
G. Arndt

As part of the search for a new cutting mechanism, a few largely empirical investigations into ultra-high-speed machining (velocity greater than 500 ft/s) have been performed in the past. A comprehensive review of this and other work related to machining at very high cutting speeds is presented and the physical factors predominating in UHSM are discussed. As a consequence of this a new theory of cutting forces at ultra-high speeds is presented, based on inertia and temperature effects, adiabatic shear, and strain-rate dependent yield stress. This theory shows that workpiece properties greatly influence force behaviour, the latter determining the feasibility of machining at ultra-high speeds.


1973 ◽  
Vol 187 (1) ◽  
pp. 625-634 ◽  
Author(s):  
G. Arndt

As part of the search for a new cutting mechanism, a few largely empirical investigations into ultra-high-speed machining (velocity greater than 500 ft/s) have been performed in the past. A comprehensive review of this and other work related to machining at very high cutting speeds is presented and the physical factors predominating in UHSM are discussed. As a consequence of this a new theory of cutting forces at ultra-high speeds is presented, based on inertia and temperature effects, adiabatic shear, and strain-rate dependent yield stress. This theory shows that workpiece properties greatly influence force behaviour, the latter determining the feasibility of machining at ultra-high speeds.


2003 ◽  
Author(s):  
Xiaowei Li ◽  
Stephane Demiguel ◽  
Ning Li ◽  
Joe C. Campbell ◽  
David Tulchinsky ◽  
...  

Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.


2009 ◽  
Vol E92-C (7) ◽  
pp. 922-928 ◽  
Author(s):  
Kikuo MAKITA ◽  
Kazuhiro SHIBA ◽  
Takeshi NAKATA ◽  
Emiko MIZUKI ◽  
Sawaki WATANABE

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