An electric optical modulator including a 1 2 multimode interference (MMI) coupler and an integrated Mach–Zehnder Interferometer (MZI) modulator that consists of a microring and a Phase Modulator (PM) is suggested in this paper. Such a modulator can achieve large output RF gain and high linearity performance at the same time. Moreover, due to the application of MMI coupler, traditional direct c...

We have designed and fabricated an out-of-plane coupler for butt-coupling from fiber to compact planar waveguides. The coupler is based on a short second-order grating or photonic crystal, etched in a waveguide with a low-index oxide cladding. The coupler is optimized using mode expansion-based simulations. Simulations using a 2-D model show that up to 74% coupling efficiency between single-mod...

We report on the fabrication and evaluation of a directional coupler consisting of two different chirped photonic crystal (PC) waveguides that can generate wideband, low dispersion slow light. The directional coupler was fabricated from a silicon-on-insulator PC slab with airhole diameter chirping. For both waveguides, we observed a group index of 60-80 near the photonic band edge and opposite ...

Two fiber Raman probes are presented, one based on an optically-poled double-clad fiber and the second based on an optically-poled double-clad fiber coupler respectively. Optical poling of the core of the fiber allows for the generation of enough 532nm light to perform Raman spectroscopy of a sample of dimethyl sulfoxide (DMSO), when illuminating the waveguide with 1064nm laser light. The Raman...

⎯An analysis of a 3 dB lumped-element directional coupler (LEDC) based on arbitrary terminal impedance is described numerically. To solve the conflicted requirement for broad bandwidth and small size in LEDC, a new structure of coupler is introduced, which can significantly improve bandwidth and whose size is only 3 cm×4 cm on the conditions of the frequency domain of 410 MHz to 490 MHz. The me...

A novel microstrip coupled-line directional coupler is proposed in this paper. It is based on the introduction of a complementary split ring resonator and dumbbell-like defected ground structure on the coupled lines to strongly enhance the designed backward coupling. The designed frequency band is from 1.2 to 1.5GHz. The coupler is fabricated and tested. The insertion loss is less than 3.5 dB. ...

A total of 190 individuals participated in a clinical visit during the Cooperative Studies Program (CSP) 418-A Long Term Follow-Up Study. Of this cohort, 158 participants were considered current hearing aid users, and 32 were non-hearing aid users. Of the current hearing aid users, 81 were still using their original 418 study devices, and 77 had acquired new hearing aids. Coupler and real ear m...

OASIS3-MCT_2.0, the new version of the OASIS coupler interfaced with MCT (Model Coupling Toolkit) released in May 2013, offers today a fully parallel implementation of coupling field regridding and exchange. In spite of the significant changes in underlying implementation, usage of OASIS3-MCT in the component code has largely remained unchanged with respect to the previous version of the couple...

A wideband microstrip forward-wave coupledline coupler with high coupling value is presented. Compared with the conventional edge-coupled microstrip forward-wave coupler, this symmetrical structure, consisting periodic shunt stubs between the two coupled-lines, achieves wider operating bandwidth and larger coupling level. To characterize this structure, the equivalent circuit model is establish...

This paper classifies the movement of the RRSS spatial linkage in terms of its link dimensions. The constraint equation for this chain relates the rotation angles of the input crank and coupler around the two revolute joints. The condition for a real valued solution for the coupler angle as a function of the input angle yields a quartic polynomial. We use three polynomial discriminants obtained...