36 research outputs found
Audiodeskrypcja autorska
Auteur Description The article outlines a new type of audio description: auteur description, which aims to immerse the blind and partially sighted audience into the story world created by the auteur-director, as presented in the screenplay. Two fi lms: Volver by Pedro Almodóvar and Dzień Świra (The Day of the Wacko) by Marek Koterski, are used to highlight the main features of auteur description: the use of metaphors, emotional and marked language, subjective descriptions, all based on the screenplay text
Versatile, open-access opto-mechanics platform for optical microscopes prototyping
Prototype optical microscopes, built to pursue developments in advanced
imaging techniques, need specific optomechanical constructions: preferably with
high flexibility in the elements arrangement, easy access to the optical paths,
straightforward integration with external optical subsystems - light sources
and detectors - as well as good mechanical stability. Typically they are either
built around an adapted commercial microscope body or as a home-built setup,
based on standard optomechanical elements, and neither solution delivers the
desired characteristics. We developed a series of versatile platforms for
prototyping optical microscopes in various configurations that use folding
mirror(s) to maintain the optical paths horizontal throughout most of the
setup, thus enabling the use of standard optical components in the excitation
and detection paths and, last but not least, increasing the laser safety of the
optical system.Comment: 11 pages, 5 figure
Heralded Generation of Ultrafast Single Photons in Pure Quantum States
We present an experimental demonstration of heralded single photons prepared
in pure quantum states from a parametric downconversion source. It is shown
that, through controlling the modal structure of the photon pair emission, one
can generate pairs in factorable states and thence eliminate the need for
spectral filters in multiple-source interference schemes. Indistinguishable
heralded photons were generated in two independent spectrally engineered
sources, and, by performing a Hong-Ou-Mandel interference between them without
spectral filters at a raw visibility of 94.4%, their purity was measured to be
over 95%.Comment: 5 pages, 4 figure
Time-frequency Domain Analogues of Phase Space Sub-Planck Structures
We present experimental data of the frequency resolved optical gating (FROG)
measurements of light pulses revealing interference features corresponding to
sub-Planck structures in phase space. For superpositions of pulses a small,
sub-Fourier shift in the carrier frequency leads to a state orthogonal to the
initial one, although in the representation of standard time-frequency
distributions these states seem to have a nonvanishing overlap.Comment: New title, minor change
Joint spectrum of photon pairs measured by coincidence Fourier spectroscopy
We propose and demonstrate a method for measuring the joint spectrum of
photon pairs via Fourier spectroscopy. The biphoton spectral intensity is
computed from a two-dimensional interferogram of coincidence counts. The method
has been implemented for a type-I downconversion source using a pair of
common-path Mach-Zender interferometers based on Soleil compensators. The
experimental results agree well with calculated frequency correlations that
take into account the effects of coupling into single-mode fibers. The Fourier
method is advantageous over scanning spectrometry when detectors exhibit high
dark count rates leading to dominant additive noise
Light-Driven Linear Inchworm Motor Based on Liquid Crystal Elastomer Actuators Fabricated with Rubbing Overwriting
Linear displacement is used for positioning and scanning, e.g., in robotics at different scales or in scientific instrumentation. Most linear motors are either powered by rotary drives or are driven directly by pressure, electromagnetic forces or a shape change in a medium, such as piezoelectrics or shape-memory materials. Here, we present a centimeter-scale light-powered linear inchworm motor, driven by two liquid crystal elastomer (LCE) accordion-like actuators. The rubbing overwriting technique was used to fabricate the LCE actuators, made of elastomer film with patterned alignment. In the linear motor, a scanned green laser beam induces a sequence of travelling deformations in a pair of actuators that move a gripper, which couples to a shaft via friction moving it with an average speed in the order of millimeters per second. The prototype linear motor demonstrates how LCE light-driven actuators with a limited stroke can be used to drive more complex mechanisms, where large displacements can be achieved, defined only by the technical constrains (the shaft length in our case), and not by the limited strain of the material. Inchworm motors driven by LCE actuators may be scaled down to sub-millimeter size and can be used in applications where remote control and power supply with light, either delivered in free space beams or via fibers, is an advantage
Spectral shearing interferometry with spatially chirped beams
info:eu-repo/semantics/nonPublishe
Programming Photoresponse in Liquid Crystal Polymer Actuators with Laser Projector
A versatile, laser-projector-based method is demonstrated for programming alignment patterns into monolithic films of liquid crystal polymer networks. Complex images can be photopatterned into the polymer films with sub-100 μm resolution, using relatively short exposure times. The method is further used to devise both photochemically and photothermally driven actuators that can undergo distinct light-induced shape changes, dictated by the programmed alignment patterns. Deformation modes such as buckling and coiling, as well as miniature robotic devices such as a gripper and a light-responsive octopod, are demonstrated. The reported technique enables easy and cost-effective programmable actuation with relatively high throughput, thus significantly facilitating the design and realization of functional soft robotic actuators.acceptedVersionPeer reviewe