Improvement in error propagation in the Shack-Hartmann-type zonal wavefront sensors

GALADRIEL: A facility for advancing engineering science relevant to rep-rated high energy density physics and inertial fusion energy experiments

Many current and upcoming laser facilities used to study high-energy-density (HED) physics and inertial fusion energy (IFE) support operating at high rep-rates (HRRs) of ∼0.1-10 Hz, yet many diagnostics, target-fielding strategies, and data storage methods cannot support this pace of operation. Therefore, established experimental paradigms must change for the community to progress toward rep-rated operation. To this end, we introduce the General Atomics LAboratory for Developing Rep-rated Instrumentation and Experiments with Lasers, or GALADRIEL, to serve as a test bed for developing and benchmarking the engineering science advancements required for HRR experiments. GALADRIEL was constructed from the ground up around a commercial 1 TW (∼25 mJ in ∼25 fs at 800 nm) laser with diverse experimental applications in mind. Assembly of the basic framework of GALADRIEL concluded with commissioning shots generating ∼1-4 MeV electrons via laser-wakefield acceleration (LWFA) using a nitrogen gas jet. Subsequent LWFA experiments operated at 1 Hz, utilized instrument feedback for optimization, and stored all data in a custom-built NoSQL database system. From this database called MORIA, or the MOngodb Repository for Information Archiving, data are retrievable via individual files or en masse by query requests defined by the user. GALADRIEL focuses on outstanding questions in engineering science, including targetry, diagnostics, data handling, environmental and materials studies, analysis and machine learning algorithm development, and feedback control systems. GALADRIEL fills a niche presently missing in the US-based user-facility community by providing a flexible experimental platform to address problems in engineering science relevant to rep-rated HED and IFE experiments.

Clinical comparison of speculum's influence on intraoperative aberrometry reading

Purpose

The aim of this study was to evaluate the influence of four different types of speculums on aberrometry reading (OPD SCAN III [OPD]) and on intraoperative aberrometry reading (optiwave response analyzer, ORA).

Patients and methods

This prospective, controlled, comparative study of consecutive cases included the evaluation of five eyes of five patients with monofocal intraocular lens (IOL) implantation. Seventeen measures were performed on each patient: for each speculum, there were two measurements on the OPD and another two on ORA with four different types of blepharostats. A control measure was performed on the without blepharostat in the dominant eye of each patient, therefore totalizing 85 measurements. The measures with the blepharostats were as follows: without pressure (WF) or passive measure and after pressure (AF) or active measure to close the eye. The speculum used in all patients was as follows: open-edged wire (Barraquer); threaded with open blade (Lieberman), with 21 mm aperture; wired with solid blade (Barraquer); and threaded with solid blade (Lieberman) with 21 mm opening. An evaluation of the objective refractive data from the OPD and ORA and the corneal astigmatism from the OPD was performed.

Results

Spherical equivalent (SE) of the OPD with the use of blepharostat compared to the OPD without speculum presented only 37.5% of results without statistical significance. Regarding the SE of ORA with speculum usage, compared to the OPD without blepharostat, only 12.5% were not significant. Regarding the accuracy of the ORA refractive axis with the use of blepharostats, all results presented statistical significance.

Conclusion

Thus, in the present study, we reached the conclusion between the studied blepharostats that the most suitable for use in the aphakic and pseudophakic capture of the ORA is the open blade threaded blepharostat (Lieberman).

Measurement of wavefront curvature using computer-generated holograms

The present article is dedicated to the problem of computer-generated holograms application for measurement of optical wavefront curvature with high precision. A holographic wavefront sensor scheme based on a phase-only spatial light modulator, which is used for CGH displaying, is proposed. The presented optical scheme and processing algorithm are validated with numerical simulations and experimental modelling.