We report a general approach to the design of broadband waveguide couplers. A double-parallel grating assembly is used to cancel the first chromatic order, and a proper choice of prism glass and base angle is made to compensate for the second chromatic order. The technique was applied to a Corning glass 7059 waveguide, and a spectral bandwidth of 70 nm was measured by the use of two complementa...

High-efficiency single-order grating coupling between an optical waveguided mode and a volume wave is achieved by means of a double-sided corrugated cover film that has phase-shifted undulations. A greater than 90% outcoupling ratio into air is demonstrated for weakly guiding ion-exchanged waveguides. The conditions for efficient coupling and the tolerances on them are established.

We demonstrate the fabrication by direct laser writing and the operation of a directional coupler containing Bragg gratings in each waveguide. We achieve high-precision control over the longitudinal shift between the gratings, which feature first-order Bragg resonance at telecommunication wavelengths. We observe fundamental differences between light transmission characteristics in couplers with...

3D FEM simulation of millimeterscale, complex electro-optically induced waveguide based devices demands the use of grids with more than several million nodes. Hence, the simulation could take substantial time and require large amounts of available memory. This paper presents a computation algorithm based on the conversion of an initial 3D waveguide structure into an analogous 2D structure, wher...

Slot waveguides are becoming more and more attractive optical components, especially for chemical and bio-chemical sensing. In this paper an accurate analysis of slot waveguide fabrication tolerances is carried out, in order to find optimum design criteria for either homogeneous or absorption sensing mechanisms, in cases of low and high aspect ratio slot waveguides. In particular, we have focus...

BACKGROUND We describe the design, the construction and performance of a narrow band ortho-mode transducer, currently used in the 5 GHz polarimetric receiver of the Galactic Emission Mapping project. RESULTS The ortho-mode transducer was designed to achieve a high degree of transmission within the 400 MHz of the GEM band around the 5 GHz (4.8-5.2 GHz). It is composed of a circular-to-square w...

A novel ultra-short polarization beam splitter (PBS) based on a bent directional coupler is proposed by utilizing the evanescent coupling between two bent optical waveguides with different core widths. For the bent directional coupler, there is a significant phase-mismatch for TE polarization while the phase-matching condition is satisfied for TM polarization. Therefore, the TM polarized light ...

We present the design of a three-dimensional (3D) polarization beam splitter (PBS) with a copper nanorod array placed between two silicon waveguides. The localized surface plasmon resonance (LSPR) of a metal nanorod array selectively cross-couples transverse electric (TE) mode to the coupler waveguide, while transverse magnetic (TM) mode passes through the original input waveguide without coupl...

We experimentally demonstrate on-chip mode-selective wavelength conversions based on the degenerate four-wave mixing (FWM) nonlinear effect in a few-mode silicon waveguide. A multimode waveguide with tapered directional coupler based mode (de)multiplexers is designed and fabricated. Using signals with advanced modulation formats all-optical wavelength conversions of 102.6-Gb/s OFDM-QPSK signals...

Abstract We propose a waveguide-based near-eye display featuring dual-channel exit pupil expander, which is composed of an in-coupler, relay gratings, and out-coupler. Unlike the conventional displays, whose field views are usually non-split or partially split, our expander able to evenly split view into two halves. The greatest benefit doing so that upper limit could be significantly increased...