We demonstrate a single frequency, 1.55 m wavelength laser based on an asymmetric twin-waveguide structure using a single growth step and a simple fabrication process. The external Bragg grating is formed on the passive ridge waveguide, optically coupled to the twin-guide gain section using a low loss, tapered mode transformer. The grating is produced by near-field holographic printing using a ...

We have proposed and demonstrated a wide-angle thermooptic variable optical attenuator using a new type of truncated asymmetric Y-branch waveguide in polymers. The asymmetric parameters in the truncated zone and also the asymmetric waveguide widths of the branch depend on its cross-talk (CT), attenuation efficiency and the length of the device or the packing density. An analysis for the optimum...

We present a new approach to engineering broadband sources of entangled photon pairs for quantum interferometry. The source is based on quasi-phase-matched spontaneous parametric down conversion in a titanium diffused periodically poled lithium niobate waveguide with a strongly-chirped poling period. The proposed non-standard asymmetric poling mitigates phase distortions associated with the pro...

We examine an example of spontaneous symmetry breaking in a double-well waveguide with a symmetric potential. The ground state of the system beyond a critical power becomes asymmetric. The effect is illustrated numerically, and quantitatively analyzed via a Galerkin truncation that clearly shows the bifurcation from a symmetric to an asymmetric steady state. This phenomenon is also demonstrated...

We investigate theoretically properties of partially coherent solitons in optical nonlinear media with slow saturable nonlinearity. We have found numerically that such a medium can support spatial solitons which are asymmetric in shape and are composed of only a finite number of modes associated with the self-induced waveguide. It is shown that these asymmetric spatial solitons can propagate ma...

A tunable channel-drop filter as essential component for the wavelength-division-multiplexing optical communication system has been demonstrated, which is based on polymer waveguide Bragg reflectors. For an ordinary Bragg reflector, the filtered signal is reflected toward the input waveguide. Thus an external circulator is required to separate the filtered signal from the input port, though it ...

A broadband zeroth-order resonant (ZOR) antenna based on asymmetric coplanar waveguide (ACPW) is presented. By adopting the epsilon negative transmission line (ENG-TL), a zeroth-order resonance mode can be achieved. We employ an asymmetric coplanar waveguide structure which offers the design freedom to realize the broadband ZOR antenna, where the antenna’s bandwidth is characterized by the equi...

We investigate optical response of a linear waveguide quantum electrodynamics (QED) system, namely, an cavity coupled to waveguide. Our analysis is based on exact diagonalization the overall Hamiltonian and therefore rigorous even in ultrastrong coupling regime QED. Owing counter-rotating terms cavity-waveguide coupling, motion amplitude phase space elliptical general. Such becomes remarkable d...

A highly sensitive refractive index sensor based on grating-assisted strip waveguide directional coupler is proposed. The sensor is designed using two coupled asymmetric strip waveguides with a top-loaded grating structure in one of the waveguides. Maximum light couples from one waveguide to the other at the resonance wavelength, and the change in resonance wavelength with the change in refract...