Large- and small-signal dynamic behavior of high-speed dual-polarization quantum-well semiconductor lasers

1997 ◽  
Vol 3 (2) ◽  
pp. 279-289 ◽  
Author(s):  
L.V.T. Nguyen ◽  
A.J. Lowery ◽  
D. Novak
1994 ◽  
Vol 05 (01) ◽  
pp. 1-44 ◽  
Author(s):  
RADHAKRISHNAN NAGARAJAN ◽  
DANIEL TAUBER ◽  
JOHN E. BOWERS

The strategy and methods to design high speed semiconductor lasers are reviewed here. The formalism for the analysis of intensity modulation, frequency modulation and intensity noise in quantum well lasers is first derived. Using this formalism the process of optimizing the laser structure for high speed operation is presented. In addition to the conventional factors such as the differential gain, photon density, photon lifetime and device parasitics, we also review the critical effects of carrier transport and microwave signal transmission on the dynamic characteristics and design of high speed semiconductor lasers.


2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.


2000 ◽  
Author(s):  
William J. Siskaninetz ◽  
Hank D. Jackson ◽  
James E. Ehret ◽  
Jeffrey C. Wiemeri ◽  
John P. Loehr

1986 ◽  
Vol 22 (7) ◽  
pp. 396 ◽  
Author(s):  
J.M. Wiesenfeld ◽  
R.S. Tucker ◽  
P.M. Downey ◽  
J.E. Bowers

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