Couplers and hybrids are devices in which two transmission lines pass close enough to each other for energy propagating on one line to couple to the other line. A 3dB 90° or 180° hybrid splits an input signal into two equal amplitude outputs. A directional coupler normally splits an input signal into two unequal amplitude outputs. This terminology “directional coupler”, “90° hybrid”, and “180° ...

We propose the use of binary slanted surface-relief gratings with parallel-groove walls as input and output couplers in a planar optical interconnect. Parametric optimization of cascaded output couplers is employed to design an interconnect consisting of N output couplers producing a uniform intensity distribution with a high efficiency that may be realized in one lithographic etching step. The...

This thesis presents the development of integrated silicon photonic devices. These devices are compatible with the present and near future CMOS technology. High-k horizontal grating couplers and waveguides are proposed. This work consists of simulations and device design, as well as the layout for the fabrication process, device fabrication, process development, characterization instrument deve...

Novel dual-band 90◦ couplers with arbitrary power division ratios using simplified composite right-/left-handed (SCRLH) transmission lines (TLs) are proposed. With a degree of freedom in the structural parameters, a SCRLH stub can easily be tailored to imitate a conventional 90◦ section at two arbitrary frequencies with different characteristic impedances, making the resulting couplers with cus...

The imbalance and excess loss in multimode interference couplers with fabrication errors are examined. Remarkably, there exists a number of optimum access waveguide widths which give a minimum imbalance. Furthermore, quite low excess loss can be simultaneously achieved by choosing one particular optimum width. It is also shown that paired interference couplers have better imbalance performance ...

In this paper a new procedure for designing forward-wave directional couplers using periodic shunt short circuited stubs is proposed. A new type of cell using these stubs, which enlarge the phase difference between even- and odd modes of a uniform microstrip coupled line is introduced. Using the equivalent circuit model for even- and odd-modes of the proposed cell, the elements of the  ABCD tra...

The design of input power couplers represents one of the most important challenges of accelerators that use super-conducting RF technology. These devices must fulfil several functions while being subject to mechanical, electromagnetic, vacuum and cryogenic constraints. The rapidly increasing number of projects, planned or under construction, which propose to use super-conducting cavities has pr...

We describe the optical and mechanical design, construction philosophy, and testing of a pair of matched, spaceflight-qualified fiber couplers. The couplers were developed for the LISA Pathfinder mission but are relevant for other applications-both on ground and in space-where a robust fiber coupler with well-controlled beam parameters and stable beam pointing is required. This particular imple...

Sub-micronic grating couplers have been integrated on optical waveguides for efficient light in-coupling into interferometric biosensors. Design and fabrication processes are presented as well as the results of the optical characterization and the sensing evaluation. Keywords-Grating couplers; interferometers; biosensors; integrated optics.