A novel backward microstrip coupled-line coupler which has been designed based on the metamaterial and composite right/left handed (CRLH) transmission line (TL) concepts is proposed. Coupling coefficient, bandwidth and size of proposed microstrip coupler are improved by coupled interdigital TLs which have been realized only by one interdigital capacitor. The design procedure to reach the couple...

An all-fiber-ring resonator has been constructed using a single strand of single-mode optical fiber and a directional coupler. Derivation of the resonator finesse in terms of fiber and directional coupler parameters is given. A finesse of 80 has been achieved experimentally. Applications of such a fiber-ring resonator are discussed.

BACKGROUND  Compared with hand-sewn anastomoses, microvascular anastomotic coupling devices (MACDs) provide equivalent flap survival and reduced operative time. To date, an economic analysis of MACDs has not been reported. The objective of this study was to evaluate the economics of a venous anastomosis performed using a coupling device compared with a hand-sewn anastomosis. METHODS  Economic...

We demonstrate the first all-chalcogenide ring fiber laser as well all chalcogenide Brillouin laser. The compact device is made from combination of an As2Se3 optical coupler for insertion pump light and extraction light, As2S3 nonlinear gain to ensure oscillation. Thanks strong As2S3, only 3m amplifying required reach threshold, thus making a resonant cavity with free spectral range significant...

A novel configuration of an interferometric device, based on a full-cycle full (100%) coupler structure, loaded with a Bragg grating symmetrically placed into the uniform coupler waist, is proposed for use as an optical add–drop multiplexer (OADM) with simultaneously optimized add and drop actions. A general method for designing a suitable Bragg grating for optimal inscription in to the uniform...

A low-loss, broadband and high fabrication tolerant optical coupler for the monolithic integration of Si3N4 and polymer waveguides is designed and experimentally demonstrated. The coupler is based on the adiabatic vertical tapering of the Si3N4 waveguides. Low-loss operation is experimentally verified at both 976 and 1460-1635 nm wavelengths. Measured losses per coupler are as low as 0.12 and 0...

Coupling phenomena between artificial left-handed ~LH! transmission lines are explored on the basis of a transmission line approach of LH materials. A LH forward coupler in the form of an ideal lumped-element ladder network is presented and is shown to exhibit strong forward coupling that increases with decreasing of frequency. A quasi-lumped element microstrip implementation of a LH coupler is...

A novel branch-line coupler which can operate at two frequencies is presented in this paper. The proposed planar topology, which is different from the conventional one, is analyzed and designed. The new coupler maintains not only compact but also dual-band characteristics. The length of the proposed stepped-impedance lines can be adjusted flexible according to the required operation frequency. ...

A silicon-on-insulator grating coupler with a broad 1-dB bandwidth of 76nm and a coupling efficiency similar to that of a standard grating coupler is experimentally demonstrated. The design is based on a novel two-way-fed method. OCIS codes: (050.0050) Diffraction and gratings; (130.0130) Integrated optics