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

Cell phones and other portable devices are equipped with a variety of technologies by which existing functionality can be improved, and new functionality can be provided. Some relate to visual search capabilities, and determining appropriate actions responsive to different image inputs. Others relate to processing of image data. Still others concern metadata generation, processing, and representation. Yet others relate to coping with fixed focus limitations of cell phone cameras, e.g., in reading digital watermark data. Still others concern user interface improvements. A great number of other features and arrangements are also detailed.

Methods and Systems for Content Processing

This article reviews the progress of atomic force microscopy in ultrahigh vacuum, starting with its invention and covering most of the recent developments. Today, dynamic force microscopy allows us to image surfaces of conductors and insulators in vacuum with atomic resolution. The most widely used technique for atomic-resolution force microscopy in vacuum is frequency-modulation atomic force microscopy (FM-AFM). This technique, as well as other dynamic methods, is explained in detail in this article. In the last few years many groups have expanded the empirical knowledge and deepened our theoretical understanding of frequency-modulation atomic force microscopy. Consequently spatial resolution and ease of use have been increased dramatically. Vacuum atomic force microscopy opens up new classes of experiments, ranging from imaging of insulators with true atomic resolution to the measurement of forces between individual atoms.

https://hep.physics.utoronto.ca/WilliamTrischuk/courses/phy189/AFM_revmodphys.pdf

Advances in atomic force microscopy

The Young's modulus (E) of a material is a key parameter for mechanical engineering design. Silicon, the most common single material used in microelectromechanical systems (MEMS), is an anisotropic crystalline material whose material properties depend on orientation relative to the crystal lattice. This fact means that the correct value of E for analyzing two different designs in silicon may differ by up to 45%. However, perhaps, because of the perceived complexity of the subject, many researchers oversimplify silicon elastic behavior and use inaccurate values for design and analysis. This paper presents the best known elasticity data for silicon, both in depth and in a summary form, so that it may be readily accessible to MEMS designers.

/pdf/what-is-the-young-s-modulus-of-silicon-1dse7n0e06.pdf

What is the Young's Modulus of Silicon?

The coupling of optical and mechanical degrees of freedom is the underlying principle of many techniques to measure mechanical displacement, from macroscale gravitational wave detectors to microscale cantilevers used in scanning probe microscopy. Recent experiments have reached a regime where the back-action of photons caused by radiation pressure can influence the optomechanical dynamics, giving rise to a host of long-anticipated phenomena. Here we review these developments and discuss the opportunities for innovative technology as well as for fundamental science.

http://science.sciencemag.org/content/sci/321/5893/1172.full.pdf

Cavity Optomechanics: Back-Action at the Mesoscale

A new miniaturized camera system that is capable of 3-dimensional imaging in real-time is presented. The compact imaging device is able to entirely capture its environment in all three spatial dimensions. It reliably and simultaneously delivers intensity data as well as range information on the objects and persons in the scene. The depth measurement is based on the time-of-flight (TOF) principle. A custom solid-state image sensor allows the parallel measurement of the
phase, offset and amplitude of a radio frequency (RF) modulated light field that is emitted by the system and reflected back by the camera surroundings without requiring any mechanical scanning parts. In this paper, the theoretical background of the implemented TOF principle is presented, together with the technological requirements and detailed
practical implementation issues of such a distance measuring system. Furthermore, the schematic overview of the complete 3D-camera system is provided. The experimental test results are presented and discussed. The present camera system can achieve sub-centimeter depth resolution for a wide range of operating conditions. A miniaturized version of such a 3D-solid-state camera, the SwissRanger 2, is presented as an example, illustrating the possibility of
manufacturing compact, robust and cost effective ranging camera products for 3D imaging in real-time.

An all-solid-state optical range camera for 3D real-time imaging with sub-centimeter depth resolution (SwissRanger)

An optomechanical sensor suitable for the study of quantum effects has been developed and characterized. The sensor reads out the vibrations of a microfabricated miniature silicon mechanical oscillator which forms one end mirror of a high finesse Fabry-P\'erot cavity. The mechanical quality factor is up to $Q=300000$ at 300 K and rises up to $Q=4\ifmmode\times\else\texttimes\fi{}{10}^{6}$ at 4 K. The thermal noise of the oscillator has been measured in the time and frequency domains at room temperature and at 4.5 K. The prospects for observing the standard quantum limit are discussed.

http://exphy.uni-duesseldorf.de/Publikationen/1999/PRA59_1038.pdf

Interferometric measurements of the position of a macroscopic body: towards observation of quantum limits

https://doc.rero.ch/record/8367/files/Berdondini_Luca_-_High-density_electrode_array_20071120.pdf

High-density electrode array for imaging in vitro electrophysiological activity

Dynamic force microscopy, a technique also known as non-contact force microscopy, has proved to be a powerful tool for atomic resolution imaging. A number of schemes have been developed, but recently the oscillator method has become the preferred operating mode. Here, the force sensor acts as resonator in an active feedback circuit. A practical implementation of the method is described and the underlying key concepts are discussed. It is shown that a tracking oscillator excitation scheme is superior to the more standard direct feedback method for cases in which the force sensor exhibits only a weak resonance enhancement. Furthermore, the simultaneous measurement of dissipative interaction channels is an important extension of dynamic force microscopy. It allows one to differentiate between sample materials via their plasto-mechanical response. As an example, a Cr test grating has been imaged in the constant force gradient mode. The dissipation measured on Cr-covered areas is significantly lower than that on the bare quartz glass substrate, which enables one to distinguish between the two materials with a lateral resolution comparable to that of the topographic image.

Dynamic force microscopy by means of the phase-controlled oscillator method

We report on the first successful operation of a scanning force microscope using microfabricated capacitive force sensors. The sensors, which are made from single crystal silicon on insulator wafers, consist of a cantilever spring with integrated tip at the free end and an electrically insulated counter electrode. Dynamic force gradient sensing is the preferred operating mode. Here, tip–sample interactions are detected by letting the sensor act as a resonator in a phase controlled oscillator setup and measuring corresponding shifts of the oscillation frequency. Experiments were performed in vacuum using a standard tunneling microscope. A Cr grating on a quartz substrate served as the test sample. Topographic images showing details on a 10 nm scale were obtained operating at a constant force gradient of the order of 0.01 N/m. In addition, critical design parameters are discussed based on an analysis of the electromechanical properties of the sensors.

/pdf/scanning-force-microscopy-in-the-dynamic-mode-using-23wsfrq7x4.pdf

Nicolas Blanc

Papers

An all-solid-state optical range camera for 3D real-time imaging with sub-centimeter depth resolution (SwissRanger)

Interferometric measurements of the position of a macroscopic body: towards observation of quantum limits

High-density electrode array for imaging in vitro electrophysiological activity

Dynamic force microscopy by means of the phase-controlled oscillator method

Scanning force microscopy in the dynamic mode using microfabricated capacitive sensors