Weak value amplification: a view from quantum estimation theory that highlights what it is and what isn't

Weak value amplification (WVA) is a concept that has been extensively used in a myriad of applications with the aim of rendering measurable tiny changes of a variable of interest. In spite of this, there is still an on-going debate about its true nature and whether is really needed for achieving high sensitivity. Here we aim at solving the puzzle, using some basic concepts from quantum estimation theory, highlighting what the use of the WVA concept can offer and what it can not. While WVA cannot be used to go beyond some fundamental sensitivity limits that arise from considering the full nature of the quantum states, WVA can notwithstanding enhance the sensitivity of real detection schemes that are limited by many other things apart from the quantum nature of the states involved, i.e. technical noise. Importantly, it can do that in a straightforward and easily accessible manner.Comment: 2 pages, 5 figure

How to automate a kinematic mount using a 3D printed Arduino-based system

We demonstrate a simple, flexible and cost-effective system to automatize most of the kinematic mounts available nowadays on the market. It combines 3D printed components, an Arduino board, stepper motors, and simple electronics. The system developed can control independently and simultaneously up to ten stepper motors using commands sent through the serial port, and it is suitable for applications where optical realignment using flat mirrors is required on a periodic basis.Comment: 9 pages, 8 figure

A 3D Printed Toolbox for Opto-Mechanical Components

Nowadays is very common to find headlines in the media where it is stated that 3D printing is a technology called to change our lives in the near future. For many authors, we are living in times of a third industrial revolution. Howerver, we are currently in a stage of development where the use of 3D printing is advantageous over other manufacturing technologies only in rare scenarios. Fortunately, scientific research is one of them. Here we present the development of a set of opto-mechanical components that can be built easily using a 3D printer based on Fused Filament Fabrication (FFF) and parts that can be found on any hardware store. The components of the set presented here are highly customizable, low-cost, require a short time to be fabricated and offer a performance that compares favorably with respect to low-end commercial alternatives.Comment: 9 pages, 9 figure

Optical sectioning in induced coherence tomography with frequency-entangled photons

We demonstrate a different scheme to perform optical sectioning of a sample based on the concept of induced coherence [Zou et al., Phys. Rev. Lett. 67, 318 (1991)]. This can be viewed as a different type of optical coherence tomography scheme where the varying reflectivity of the sample along the direction of propagation of an optical beam translates into changes of the degree of first-order coherence between two beams. As a practical advantage the scheme allows probing the sample with one wavelength and measuring photons with another wavelength. In a bio-imaging scenario, this would result in a deeper penetration into the sample because of probing with longer wavelengths, while still using the optimum wavelength for detection. The scheme proposed here could achieve submicron axial resolution by making use of nonlinear parametric sources with broad spectral bandwidth emission.Comment: Published version. 11 pages, 9 figure

Tunable beam displacer

We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.Comment: 3 pages, 2 figure

FAKTORI KOJI POMAŽU IZDVAJANJU BENTOSKIH CIJANOBAKTERIJA IZ FAZA MIROVANJA: PREGLED

The sediment-water interface in aquatic systems is an environment connecting bottom sediments with the overlying water column. This transition zone can be easily disturbed by mechanical mixing (bioturbation) caused by foraging fish and/or macroinvertebrates moving around and stirring sediment layers. The sediment of still water ecosystems is largely known as a reservoir of resting stages of various planktonic plants, including cyanobacteria (blue-green algae) and invertebrates. The ecological and evolutionary dynamics of cyanobacteria is in part a function of the numbers and ages of diapausing stages hatching from aquatic sediments. Successful recruitment from this ”seed bank” must depend upon the resting stages being present at or near the sediment surface. Often, however, they are found as deep as 15 to 30 cm in the mud. Bioturbation may thus provide a mechanism for the regular return of buried cyanobacteria resting stages to the sediment surface.Prostor površine bentala (sediment-voda) je okoliš koji povezuje sediment dna i stupac vode iznad. Ova prijelazna zona lako se može uznemiriti mehaničkim miješanjem (bioturbacijom) uzrokovanim ribom koja je u potrazi za hranom i kretanjem makrozoobentosa kroz slojeve sedimenta. Sediment ekosustava stajaćica uglavnom je poznat kao “rezervoar” za mirovanje različitih planktonskih biljaka, uključujući cijanobakterije (modrozelene alge) i beskralježnjake. Ekološka i evolucijska dinamika cijanobakterija ima utjecajnu ulogu za brojne generacijske stadije mirovanja nastale u akvatičnom ekosustavu. Uspješno izdvajanje iz tih “banki stanica” mora ovisiti o fazama mirovanja u/ili blizu površine sedimenta. Međutim, cijanobakterije se često nalaze 15 do 30 cm dubine u mulju. Mehaničko miješanje (bioturbacija) može osigurati povratak ukopanih cijanobakterija iz faza mirovanja na površinu sedimenta

Creación de un centro de estimulación temprana en el sector sur oste de la ciudad de Guayaquil

The idea of creating a Center for Early Stimulation means the implementation and adequacy of an area containing several games, they will be used for training of sensory and psychomotor children that are expected to improve their skills. The biggest problem that arises in this sector is that many families either through ignorance or lack of economic resources are not able to access the benefits they provide such treatments. Some hospitals have this service but unfortunately have a limited intake of infants, because the costs that are incurred are high, therefore the sessions are restricted. One of the most important objectives is to provide quality care with low prices and this will ensure that many children can access this service. As a result we can determine that by carrying out this project we benefit not only us in the economic but also bring in the social field, helping to improve the quality of life for children