Soliton back-action evading measurement using spectral filtering

We report on a back-action evading (BAE) measurement of the photon number of fiber optical solitons operating in the quantum regime. We employ a novel detection scheme based on spectral filtering of colliding optical solitons. The measurements of the BAE criteria demonstrate significant quantum state preparation and transfer of the input signal to the signal and probe outputs exiting the apparatus, displaying the quantum-nondemolition (QND) behavior of the experiment.Comment: 5 pages, 5 figure

Biomechanically-driven simulations of the MyoRing treatment in subjects with high myopia

Purpose: Corneal biomechanics is a determinant factor for the outcome of continuous intracorneal segments (MyoRing, Dioptex GmbH). However, implant selection remains driven by optical parameters such as the average central curvature of the cornea (Kmean) and the Spherical Equivalent (SE), while failing to account for the tissue biomechanics or the intraocular pressure (IOP). We hypothesize that biomechanical models and computer simulation can improve the refractive outcomes of the MyoRing treatment. Methods: Four thousand computer models representing the population of patients who are candidates for a MyoRing treatment have been created using the finite element method. These numerical models accounted for physiologic variability of the anatomical features (anterior and posterior corneal radius of curvature, corneal thickness, axial length and pupil size) and mechanical properties (corneal biomechanics and IOP). Two MyoRing implants were evaluated on these virtual patients (Myoring size: 280 µm; optical zone: 5 and 6 mm; depth: 60%-75%; laser ablated pocket 5 µm). Refractive outcomes obtained with the biomechanical simulation were compared to previous clinical data (Daxer 2017; Rattan 2018). Results: Population-based simulations were able to reproduce the refractive correction observed clinically; the average post-surgical Kmean was within ± 0.5 D of the data reported by Rattan (Fig.1 a), and the distribution of post-surgical SE closely matched the clinical data from Daxer (Fig.1 b). Moreover, our simulation approach allowed us to determine the clinical parameters having the most important contributions to the refractive outcome. For example, we found that the correction in Kmean is strongly related to the pre-surgical thickness, mechanics, and IOP, while the correction in SE is highly affected by the depth of MyoRing insertion. Conclusions: Biomechanical modelling is able to predict the refractive outcomes of MyoRing implantations. This approach provides a deeper understanding on the mechanisms underlying continuous intracorneal segments, which can be used to improve implant design and further personalize the treatment procedure

Four modes of optical parametric operation for squeezed state generation

We report a versatile instrument, based on a monolithic optical parametric amplifier, which reliably generates four different types of squeezed light. We obtained vacuum squeezing, low power amplitude squeezing, phase squeezing and bright amplitude squeezing. We show a complete analysis of this light, including a full quantum state tomography. In addition we demonstrate the direct detection of the squeezed state statistics without the aid of a spectrum analyser. This technique makes the nonclassical properties directly visible and allows complete measurement of the statistical moments of the squeezed quadrature

Near-field optics and control of photonic crystals

We discuss recent progress and the exciting potential of scanning probe microscopy methods for the characterization and control of photonic crystals. We demonstrate that scanning near-field optical microscopy can be used to characterize the performance of photonic crystal device components on the sub-wavelength scale. In addition, we propose scanning probe techniques for realizing local, low-loss tuning of photonic crystal resonances, based on the frequency shifts that high-index nanoscopic probes can induce. Finally, we discuss prospects for on-demand spontaneous emission control. We demonstrate theoretically that photonic crystal membranes induce large variations in spontaneous emission rate over length scales of 50 nm that can be probed by single light sources, or nanoscopic ensembles of light sources attached to the end of a scanning probe. (c) 2005 Elsevier B.V. All rights reserved