We review the field of cavity optomechanics, which explores the interaction between electromagnetic radiation and nano- or micromechanical motion This review covers the basics of optical cavities and mechanical resonators, their mutual optomechanical interaction mediated by the radiation pressure force, the large variety of experimental systems which exhibit this interaction, optical measurements of mechanical motion, dynamical backaction amplification and cooling, nonlinear dynamics, multimode optomechanics, and proposals for future cavity quantum optomechanics experiments In addition, we describe the perspectives for fundamental quantum physics and for possible applications of optomechanical devices

Cavity Optomechanics

Four decades after the development of the first dynamic substructuring techniques, there is a necessity to classify the different methods in a general framework that outlines the relations between them. In this paper, a certain vision on substructuring methods is proposed, by recalling important historical milestones that allow us to understand substructuring as a domain decomposition concept. Thereafter, based on the dual and primal assembly of substructures, a general framework for the classification of the methods is presented. This framework allows us to indicate how the various classes of methods, proposed along the years, can be derived from a clear mathematical description of substructured problems. Current bottlenecks in experimental dynamic substructuring, as well as solutions found in literature, will also be briefly discussed.

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General Framework for Dynamic Substructuring: History, Review and Classification of Techniques

A system includes a semiconductor device. The semiconductor device includes a first single crystal silicon layer comprising first transistors, first alignment marks, and at least one metal layer overlying the first single crystal silicon layer, wherein the at least one metal layer comprises copper or aluminum more than other materials; and a second single crystal silicon layer overlying the at least one metal layer. The second single crystal silicon layer comprises a plurality of second transistors arranged in substantially parallel bands. Each of a plurality of the bands comprises a portion of the second transistors along an axis in a repeating pattern.

System comprising a semiconductor device and structure

A device comprising semiconductor memories, the device comprising: a first layer and a second layer of layer-transferred mono-crystallized silicon, wherein the first layer comprises a first plurality of horizontally-oriented transistors; wherein the second layer comprises a second plurality of horizontally-oriented transistors; and wherein the second plurality of horizontally-oriented transistors overlays the first plurality of horizontally-oriented transistors.

Semiconductor device and structure

Devices, methods, and software are disclosed for determining dimensions of a physical object using a mobile computer equipped with a motion sensing device. In an illustrative embodiment, the mobile computer can comprise a microprocessor, a memory, a user interface, a motion sensing device, and a dimensioning program executable by the microprocessor. The processor can be in communicative connection with executable instructions for enabling the processor for various steps. One step includes initiating a trajectory tracking mode responsive to receiving a first user interface action. Another step includes tracking the mobile computer's trajectory along a surface of a physical object by storing in the memory a plurality of motion sensing data items outputted by the motion sensing device. Another step includes exiting the trajectory tracking mode responsive to receiving a second user interface action. Another step includes calculating three dimensions of a minimum bounding box corresponding to the physical object.

Measuring object dimensions using mobile computer

A new flexibility-based component mode synthesis method is presented, which is derived by approximating the partitioned equations of motion that employ a localized method of Lagrange multipliers. The use of the localized Lagrange multipliers leads to, unlike the classical Lagrange multipliers, a linearly independent set of interface forces without any redundancies at multiply connected interface nodes. Hence, the resulting interface flexibility matrices are uniquely determined and well suited for the present method development. An attractive feature of the present method is its substructural mode selection criterion that is independent of loading conditions. Numerical experiments show that the present modal selection criterion is reliable and that the proposed flexibility-based component mode synthesis method performs well relative to the classical Craig‐Bampton method in terms of accuracy and of its ability to include dominant substructural modes for simple plates and a relatively complex solid ring.

Partitioned Component Mode Synthesis via a Flexibility Approach

A computational model is developed for the prediction of wave propagation in the substrate of a MEMS resonator to study energy loss mechanisms from the vibrating beams to the substrate, viz., anchor loss. The model employs a modified classical Fourier transform method under periodic excitations at the anchor area. The present substrate model, when applied to a typical commercially fabricated substrate, estimates that the anchor loss of an ends-anchored resonator with its center frequency of 50 MHz can reach as high as 0.05% in terms of equivalent damping ratio. Anchor loss versus resonator center frequency is assessed by varying the beam dimension, which predicts that anchor loss increases a hundredfold for every tenfold increase in resonator center frequency in the case of two ends-anchored beam resonators. The substrate model has been integrated into a coupled beam-substrate-electrostatics model and validated with experimental data. Development of the detailed coupled-physics model and its validation is presented in Part II as a companion paper.

High-fidelity modeling of MEMS resonators. Part I. Anchor loss mechanisms through substrate

An optoelectronic shutter, a method of operating the same, and an optical apparatus including the optoelectronic shutter are provided The optoelectronic shutter includes a phototransistor which generates an output signal from incident input light and a light emitting diode serially connected to the phototransistor The light emitting diode outputs output light according to the output signal, and the output signal is gain-modulated according to a modulation of a current gain of the phototransistor

Optoelectronic shutter, method of operating the same and optical apparatus including the optoelectronic shutter

Provided are a depth camera and methods of measuring a depth image by using the depth camera. The depth camera is a time-of-flight (TOF) depth camera including: an illumination device that illuminates a patterned light to an object; a filter unit that reduces noise light included in light reflected by the object; and an image sensor that provides a depth image of the object by receiving light that enters through the filter unit. The illumination device includes: a light source; and a patterned light generator that changes the light emitted from the light source into the patterned light. The filter unit includes a band pass filter and an optical modulator. The patterned light generator may be a diffractive optical element or a refractive optical element.

Camera for measuring depth image and method of measuring depth image using the same

We designed a new electrostatically driven scanning mirror which consists of a circular mirror plate and an elliptic outer frame with vertical combs. The rotational actuation is done by the vertical combs attached to the elliptic outer frame. To increase the actuation force, stationary vertical comb electrodes are arranged on the upper and lower sides of the moving comb fingers, simultaneously. This eye-type mirror showed larger deflection angle compared to those of the previous works such as using rectangular and elliptic mirrors. The diameter of the mirror plate is 1.0 mm, and the lengths of the major and minor axes of the outer frame are 2.5 and 1.0 mm, respectively. Using this scanning mirror, we obtained an optical scanning angle of 32° when driven by sinusoidal driving voltage of system's resonant frequency in range of 22.1–24.5 kHz with 100 V dc bias voltage. We demonstrated a full color XGA-resolution video image with screen diagonal size over 30 in. using the eye-type scanning mirror.

Yong-Hwa Park

Papers

Partitioned Component Mode Synthesis via a Flexibility Approach

High-fidelity modeling of MEMS resonators. Part I. Anchor loss mechanisms through substrate

Optoelectronic shutter, method of operating the same and optical apparatus including the optoelectronic shutter

Camera for measuring depth image and method of measuring depth image using the same

Eye-type scanning mirror with dual vertical combs for laser display