Optical bias controlled amplification in tandem Si-C pinpin devices

2011 ◽  
Vol 1321 ◽  
Author(s):  
M. Vieira ◽  
M. A Vieira ◽  
P. Louro ◽  
M. Fernandes ◽  
A. Fantoni ◽  
...  
Keyword(s):  
Optical System ◽  
Optical Amplifier ◽  
High Excitation ◽  
Transient Conditions ◽  
Electrical Simulation ◽  
Excitation Frequencies ◽  
Optoelectronic Model

ABSTRACTA monolithic double pi’n/pin a-SiC:H device that combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal is analyzed under different electrical and optical bias conditions at low and high excitation frequencies. Results show that the transducer is a bias wavelength current-controlled device that make use of changes in the wavelength of the background to control the power delivered to the load. Self optical bias amplification or quenching under uniform irradiation and transient conditions is achieved. The device acts as an optical amplifier whose gain depends on the background wavelength and frequency. An optoelectronic model supported by an electrical simulation explains the operation of the optical system.

Breakdown of atmospheric pressure microgaps at high excitation frequencies

2015 ◽  
Vol 117 (17) ◽  
pp. 173303 ◽  
Author(s):  
Dmitry Levko ◽  
Laxminarayan L. Raja
Keyword(s):  
Atmospheric Pressure ◽  
High Excitation ◽  
Excitation Frequencies

Investigation of 16 × 10 Gbps DWDM System Based on Optimized Semiconductor Optical Amplifier

2017 ◽  
Vol 38 (3) ◽  
Author(s):  
Aruna Rani ◽  
Sanjeev Dewra
Keyword(s):  
Optical System ◽  
Bit Error Rate ◽  
Error Rate ◽  
Input Signal ◽  
Semiconductor Optical Amplifier ◽  
Optical Amplifier ◽  
Signal Power ◽  
Channel Spacing ◽  
Input Signal Power ◽  
Dwdm System

AbstractThis paper investigates the performance of an optical system based on optimized semiconductor optical amplifier (SOA) at 160 Gbps with 0.8 nm channel spacing. Transmission distances up to 280 km at –30 dBm input signal power and up to 247 km at –32 dBm input signal power with acceptable bit error rate (BER) and

scholarly journals Algunos errores numéricos en la respuesta del estado estable de sistemas mecánicos vibratorios

2019 ◽  
pp. 1-9
Author(s):  
Benjamín Vázquez-González ◽  
Homero Jiménez-Rabiela ◽  
José Luis Ramírez-Cruz ◽  
Adrian Gustavo Bravo-Acosta
Keyword(s):  
Steady State ◽  
Mechanical Vibration ◽  
Numerical Algorithms ◽  
Steady State Response ◽  
High Excitation ◽  
State Response ◽  
Oscillating Systems ◽  
The Common ◽  
Excitation Frequencies ◽  
The Right

In this work numerical simulation results are shown for the steady state response of linear mechanical oscillating systems and the numerical errors that can be present when some numerical algorithms are used to perform the simulations. For some numerical parameters, the mechanical oscillating system with or without damping response, does not converge to the expected steady state response; this discrepancy is not easily detected when the performance of the system is on the range of high excitation frequencies, due that for of high excitation frequencies the amplitude in the steady state response reaches very small values. We perform the time response of the system using conventionally numerical methods included in the common programming platforms, and the result is that using the same algorithm in different platforms the error is the same; selecting other numeric algorithm the result in satisfactory. Non linear forced mechanical vibration systems; behave like linear systems for some frequency range, then is very useful to obtain the right or correct responses in the steady state response for the linear system, this is fundamental for forward studies, the right analysis is based on the selected numeric algorithm.

A New High Resolution Transmission Electron Microscope with Second-Zone Objective Lens

1969 ◽  
Vol 27 ◽  
pp. 176-177 ◽  
Author(s):  
H. Tochigi ◽  
H. Uchida ◽  
S. Shirai ◽  
K. Akashi ◽  
D. J. Evins ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Objective Lens ◽  
High Excitation ◽  
Transmission Electron ◽  
New Instrument

A New High Excitation Objective Lens (Second-Zone Objective Lens) was discussed at Twenty-Sixth Annual EMSA Meeting. A new commercially available Transmission Electron Microscope incorporating this new lens has been completed.Major advantages of the new instrument allow an extremely small beam to be produced on the specimen plane which minimizes specimen beam damages, reduces contamination and drift.

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

Information and estimation in image processing

1987 ◽  
Vol 45 ◽  
pp. 14-17
Author(s):  
B. Roy Frieden
Keyword(s):  
Image Processing ◽  
Optical System ◽  
Large Amplitude ◽  
Communication Theory ◽  
Image Data ◽  
Direct Approach ◽  
Ill Posed

Despite the skill and determination of electro-optical system designers, the images acquired using their best designs often suffer from blur and noise. The aim of an “image enhancer” such as myself is to improve these poor images, usually by digital means, such that they better resemble the true, “optical object,” input to the system. This problem is notoriously “ill-posed,” i.e. any direct approach at inversion of the image data suffers strongly from the presence of even a small amount of noise in the data. In fact, the fluctuations engendered in neighboring output values tend to be strongly negative-correlated, so that the output spatially oscillates up and down, with large amplitude, about the true object. What can be done about this situation? As we shall see, various concepts taken from statistical communication theory have proven to be of real use in attacking this problem. We offer below a brief summary of these concepts.

Atomic Resolution in Crystal Aperture Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 236-237
Author(s):  
J T Fourie
Keyword(s):  
Optical System ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Transmission Function ◽  
Optical Systems ◽  
Bragg Angle ◽  
Electron Optical System ◽  
Intimate Contact ◽  
Diffraction Effects ◽  
Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

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