Specific structural changes in Sc/Si multilayer mirrors irradiated with extreme ultraviolet (EUV) laser single pulses (λ = 46.9 nm) at near damage threshold fluences (0.04–0.23 J cm−2) are analysed. We have identified melting of surface layers as the basic degradation mechanism for the mirrors. Both heat generation during silicide formation and low heat conduction of the layered system signific...

We show that the optomechanical coupling between an optical cavity mode and the two movable cavity end mirrors is able to entangle two different macroscopic oscillation modes of the mirrors. This continuous variable entanglement is maintained by the light bouncing between the mirrors and is robust against thermal noise. In fact, it could be experimentally demonstrated using present technology. ...

After advent of graphene as a saturable absorber many experiments have been conducted to produce short pulse duration pulses. Here, we have measured the properties of flake-graphene saturable absorber mirrors of various flake sizes dependent on fabrication technique. These mirrors enabled us to obtain a large mode-locking bandwidth of 16nm in an erbium-doped fiber laser. Mirrors with large flak...

If an observer, at rest (in flat spacetime) between a pair of mirrors each at distance D but in opposite directions, emits two pulses of light simultaneously they return to the observer simultaneously after time 2D/c, where c is the speed of light. Discuss the case that the observer and mirrors have uniform acceleration (with respect to the inertial lab frame) along their common line. Compare w...

We present an automatic camera and mirrors placement method for visualizing 3D scenes such that complete and nonredundant visibility is guaranteed, as well as highest image resolution. We provide algorithms and geometries for optimal object-independent mirrors and viewpoint placement for all objects in a specific class. We also briefly consider object-dependent algorithmic problems, where mirro...

We show that, given finitely many line-segment mirrors in the plane, that do not touch, and an arbitrary point source of light, if all angles made by lines parallel to mirrors are rational multiples of π, then all but countably many emitted light beams escape. This result is shown to imply that, for a given point source of light, a randomly chosen configuration of finitely many nontouching line...

Popular User-Review Social Networks (URSNs)— such as Dianping, Yelp, and Amazon—are often the targets of reputation attacks in which fake reviews are posted in order to boost or diminish the ratings of listed products and services. These attacks often emanate from a collection of accounts, called Sybils, which are collectively managed by a group of real users. A new advanced scheme, which we te...

The design, manufacture, and testing of optical quality surface micromachined deformable mirrors (DMs) is described. With such mirrors, the shape of the reflective surface can be modified dynamically to compensate for optical aberrations and thereby improve image resolution in telescopes or microscopes. Over several years, we have developed microelectromechanical system (MEMS) processing techno...

Space observations of fainter and more distant astronomical objects constantly require telescope primary mirrors with larger sizes. The diameters of monolithic primary mirrors are restricted to 10 m because of manufacturing limitations. For space telescopes, the primary mirrors are limited to less than 5 m due to fairing capacity. Segmented primary mirrors thus constitute an alternative solutio...