Numerical analysis of optical vortices generation with nanostructured phase masks

We study the theoretical formation of optical vortices using a nanostructured gradient index phase mask. We consider structures composed of spatially distributed thermally matched glass nanorods with high and low refractive indices. Influence of effective refractive profile distribution, refractive index contrast of component glasses and charge value on the quality of generation of vortices are discussed. A trade-off between waveguiding and phase modulation effects for various refractive index contrast is presented and analysed.Qatar National Research Fund (NPRP12S-0205-190047); Fundacja na rzecz Nauki Polskiej (POIR.04.04.00-00-1C74/16)

Formation of optical vortices with all-glass nanostructured gradient index masks

We report the development of microscopic size gradient index vortex masks using the modified stack-and-draw technique. The vortex mask has a form of flat surface all-glass plate. Its functionality is determined by an internal nanostructure composed of two types of soft glass nanorods. The generation of optical vortices with charges 1 and 2 is demonstrated.Qatar National Research Fund (NPRP8-246-1-060); Foundation for Polish Science Team Programme from the funds of European Regional Development Fund under Smart Growth Operational Programme (TEAM TECH/2016-1/1)

Formation of optical vortices with all-glass nanostructured gradient index masks

We report a development of microscopic size gradient index vortex masks using modified stack-and-draw technique. Vortex mask has a form of tens of microns thick, flat-surface all-glass plate. Its functionality is determined by internal nanostructure composed of two types of soft glass nanorods. Their spatial arrangement ensures that the average refractive index mimics continuous refractive index distribution imposing azimuthal phase modulation of optical beam. The mask of thickness of 40 microns is used to demonstrate generation of optical vortices with charges 1 and 2, in the femtosecond and cw regimes, respectively.Qatar National Research Fund (NPRP8-246-1-060) and TEAM TECH/2016-1/1 (Foundation for Polish Science Team Programme from the funds of European Regional Development Fund under Smart Growth Operational Programme)

Optical characterization of single nanostructured gradient index vortex phase masks fabricated by the modified stack-and-draw technique

The optical performance of nanostructured gradient index vortex phase masks (VPMs) in various external media was investigated. We utilized a modified stack-and-draw technique to fabricate the microscopic-size masks. Its structure contains spatially distributed sub-wavelength rods made of two thermally matched glasses with high and low refractive indices. Measured optical characteristics of the generated vortices with azimuthal phase distribution are presented. The numerical and experimental study shows that such VPMs with the same designed structure but varied thickness can convert fundamental light beam into optical vortices with different charges. Furthermore, we found that the mask performance is unaffected by the refractive index of the surrounding media making it an excellent candidate for microfluidic applications.This work was supported by the project POIR.04.04.00-1C74/16 operated within the Foundation for Polish Science Team Programme co-financed by the European Regional Development Fund under Smart Growth Operational Programme (SG OP), Priority Axis IV. W.K. ac- knowledges support from Qatar National Research Fund (grant# NPRP 9-020-1-006)

Three-Dimensional-Printed Mechanical Transmission Element with a Fiber Bragg Grating Sensor Embedded in a Replaceable Measuring Head

Compliant mechanisms have gained an increasing interest in recent years, especially in relation to the possibility of using 3D printers for their production. These mechanisms typically find applications in precise positioning systems of building robotic devices or in sensing where they can be used to characterize displacement. Three-dimensional printing with PLA materials allows fiber optic-based sensors to be incorporated into the structures of properly designed compliant mechanisms. Therefore, in this paper, an innovative technology is described, of a Fiber Bragg Grating (FBG) sensor embedded in a measuring head which was then inserted into a specially designed mechanical transmission element. The shape of this element is based on clippers that allow to freely modify the amplification of displacement amplitude so that the FBG sensor always works in the most optimal regime without any need to modify its external dimensions. Flexural sensitivity of the replaceable measuring head equal to 1.26 (mε/mm) can be adapted to the needs of the flexure design