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

It has recently been shown that shared cryptographic quan tum bits are achievable through the use of an optical coupler instead of polarised photons We show that such shared cryptographic bits can also be produced by using a di erent optical apparatus a beam splitter An important advantage of such a system is that it could be experimentally more feasible than an optical coupler

A novel technique of using a 1 x N star fiber optic coupler as a distributed strain sensor in a white-light interferometer to measure the distribution of strain is presented. The measuring principle and 1 x 4 star coupler with four fiber optic strain sensors are demonstrated. The experiment is performed with four sensors attached to a combination plastic specimen.

Mitotic chromosome motions are driven by microtubules (MTs) and associated proteins that couple kinetochores to MT ends. A good coupler should ensure a high stability of attachment, even when the chromosome changes direction or experiences a large opposing force. The optimal coupler is also expected to be efficient in converting the energy of MT depolymerization into chromosome motility. As was...

Abstract—This paper presents a miniaturized branch-line coupler with suppression of wideband harmonics based on a unit of transmission-line section with triple-stub. This fundamental unit produces three transmission zeros and exhibits wide stopband response due to the triple stubs. It is used to replace a quarter-wavelength line in conventional branch-line coupler, leading to size reduction and...

We report our study on nonlinear parity-time (PT) symmetric coupler from a dynamical perspective. In the linear regime, the differential equations governing the dynamics of the coupler, under some parametric changes, can be solved exactly. But with the inclusion of nonlinearity, analytical solution of the system is a rather complicated job. And the sensitiveness of the system on the initial con...

High current SRF technology is being explored in present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input ...

Results of a theoretical and experimental investigation into the variation of coupling efficiency with coupling angle are presented for various beam focusing conditions for an integrated optical grating coupler. This investigation shows that the acceptance angle of the grating coupler can be broadened, within a relatively large range and with a relatively small loss of coupling efficiency, by f...

We present the design of a short broadband fiber directional coupler for terahertz (THz) radiation and demonstrate a 3 dB coupler with a bandwidth of 0.6 THz centered at 1.4 THz. The broadband coupling is achieved by mechanically downdoping the cores of a dual-core photonic crystal fiber by microstructuring the cores. This is equivalent to chemical downdoping but is easier to realize experiment...

Recent progress in research on optical fiber devices, especially optical fiber couplers and optical fiber grating couplers, by a new fabrication method, that is, a CO2 laser irradiation method is reviewed. Furthermore, applications of optical fiber grating couplers are also described. Key-words: Optical Fiber Device, Optical Fiber Coupler, Optical Fiber Grating Coupler