The photonics and optics workforce: unleashing the potential for greater industry growth-introduction to the feature issue.

This feature issue highlights specific photonics and optics workforce challenges, opportunities for industry support, and state-of-the-art-training methods.

Evanescent coupling to silicon waveguides using surface plasmon polaritons.

In this work, we discuss evanescent light coupling to silicon waveguides using surface plasmon polaritons (SPPs) in the Otto configuration. The setup for excitation of SPPs includes a fused-silica prism, a 100 nm silver layer with a 650 nm airgap between them, and a tapered silicon waveguide located across from the silver layer. A $p$p-polarized light of 1550 nm wavelength is incident at plasmonic angle of 44° to the interface of the fused silica-airgap to excite the SPP. A 2D Lumerical FDTD Solutions simulation shows a coupling efficiency of 54%. The fabricated device on a silicon-on-insulator substrate shows 10% light transmission for $p$p-polarized light.

Low-MSE extraction of permittivity in optical hyperbolic metamaterials.

We describe the details of a procedure to obtain low mean-squared-error (MSE) values for the extraction of permittivity tensors of hyperbolic metamaterials (HMMs) using spectroscopic ellipsometry. We have verified our procedure through characterization of three different HMM samples having varying materials, periods, and fill factors. Our procedure eliminates the need for complicated ellipsometric measurements and modeling techniques, as well as the need for any additional optics such as prisms or index-matching gels. Therefore, a time-efficient and cost-effective approach is introduced, which is only dependent on software; hence, it can be easily and widely adopted. All the MSE values obtained in this Letter are below 1.00 while, at the same time, meaningful and reasonable permittivities are extracted from HMMs.

Ultracompact polarizing beam splitter based on single-material birefringent photonic crystal.

An ultracompact polarizing beam splitter (PBS) is designed and fabricated based on a single-material birefringent photonic crystal structure. The fabrication method is based on e-beam physical vapor deposition where an oblique angle deposition technique is also incorporated. The PBS is designed for high tolerances in volume production. The main ingredient of the PBS is an alternating high- and low-refractive-index modulation created from titanium dioxide deposited at angles of 0° and 70°. The measurements exhibited successful separation of two states of polarization with efficiencies of more than 92% over a total device length of under 6 µm.