Abstract: Segmented waveguide structures provide mode matching in planar lightwave circuits between waveguides and other waveguiding structures, e.g. slab waveguides and optical fibers. The present invention eliminates back reflections from the core segments by etching the leading and trailing faces of the core segments with a plurality of parallel facet sections, which are rearwardly offset in the transmission direction by an odd number of quarter wavelengths.

Abstract: The present invention relates to a hybrid planar lightwave circuit in which a silicon reflective diffraction grating etched with a highly accurate deep reactive ion etching process is mounted in a trench formed in a high optical performance silica on silicon waveguide device.

Abstract: Ridge and buried waveguide structures feature a plurality of trenches disposed proximate the waveguides in order to enhance confinement of an optical signal propagating within the waveguide are described. Additionally, an adiabatic transition region where the distance between trenches and waveguide is featured.

Abstract: A reflector chip of the present invention integrates a planar lightwave circuit (PLC) waveguide wafer and an active component, such as a photo-detector or laser, e.g. vertical cavity surface emitting laser. Typically, the PLC waveguide wafer includes a waveguide core region bound by upper and lower cladding layers. An end of the waveguide core region is mounted within a channel, trench, notch or recess within the bottom surface of the body of the reflector chip. A V-notch is also formed in the bottom surface of the body of the reflector, including a reflective surface, which redirects the light between the active component and the waveguide core region.

Abstract: A planar lightwave circuit including a slab waveguide, with a plurality of different diffraction filtering elements optically coupling a plurality of input and output ports, provides various optical functionalities including multiplexing, demultiplexing, diplexer and triplexer. In the basic configuration one or more output ports are optically coupled to an input port via grating filters etching in the cladding of the slab waveguide, and an additional port is optically coupled to the input port via a diffraction grating etched in an endwall of the slab waveguide. A triplexer platform can be provided by optically coupling photo-detectors to two output ports, which receive wavelength channels demultiplexed from an input signal by two cladding etched filters, and by optically coupling a laser to another input port, which launches an outgoing laser signal at the endwall etched grating filter for coupling into the same fiber that launched the original input signal.

Abstract: An optical triplexer design is described in which external optical signals at a first wavelength range propagate through a laser source. The laser source provides optical signals having a second wavelength range. The triplexer features a photodetector for providing intensity feedback signals to the lasers source and a dense wavelength division multiplexer for demultiplexing the external optical.

Abstract: An Echelle grating has alternate first (1a) and second (1b) sets of facets (1). The first set of facets (1a) is operative to reflect incident light (4) for diffraction and the second set of facets (1b) extends between adjacent facets of the first set (1a). Only the first set of facets (1a) is metallized to enhance reflection. The second set of facets (1b) is left unmetallized. This configuration reduces polarization dependent loss (PDL).

Abstract: The invention relates to a planar waveguide reflective diffraction grating for use in an optical device, such as a wavelength division multiplexer, providing an increased bandwidth over conventional planar waveguide reflection diffraction gratings while eliminating the polarization dependent loss (PDL) typically associated therewith. The multiplexer/demultiplexer according to the present invention includes input and output ports optimally positioned in accordance with the grating facet diffraction envelope to minimized back reflection to the input ports and maximize output light collected from different diffraction orders.

Abstract: A method for integrating power monitoring capabilities with passive demultiplexing operations, utilizing the high-order diffraction from an optical diffraction grating. The technique helps avoid insertion loss and polarization dependent loss penalties, and device size penalties, typically incurred with optical taps and multiple diffraction gratings. The technique can also be modified slightly to provide information on channel wavelength and optical signal-to-noise-ratio, as well as channel power.

Abstract: An optical performance monitor for measuring the performance of optical networks has an echelle grating for demultiplexing an input beam into a plurality of wavelengths that are focused onto an array of divided output waveguides. Each divided output waveguide is positioned to receive a corresponding demultiplexed wavelength from the echelle grating or other waveguide multiplexer device. The divided output waveguides laterally separate the corresponding demultiplexed wavelength into a first and second portions. A detector array is positioned to receive the respective portions of the demultiplexed wavelengths and by comparing their relative intensity it is possible to detect any drift in the nominal wavelengths of the channels.

Abstract: The invention relates to a planar lightwave circuit including a two stage optical filter for use in a bi-directional transceiver. A first stage includes a non-dispersive optical filter, which enables light within in a certain wavelength range, e.g. a signal channel from a laser source, to be launched onto an input/output waveguide, while light within another wavelength range, e.g. one or more detector channels, will be directed from the input/output waveguide to a second stage. The second stage includes a reflective diffraction grating with a higher resolution than the first stage providing passbands 2 to 5 times thinner than the first stage.

Abstract: The invention relates to a planar waveguide reflective diffraction grating for use in an optical device, such as a wavelength division multiplexer, providing an increased bandwidth over conventional planar waveguide reflection diffraction gratings while eliminating the polarization dependent loss (PDL) typically associated therewith. Accordingly, a low order (<3), high aspect ratio (>10) grating is provided with a very short side wall (less than the wavelength of the optical signal) for use with incident angles of less than 15°.

Abstract: The invention relates to a double-grating subtractive-dispersion optical channel multiplexer/demultiplexer for combining or separating optical channels and providing the output channels with a flat-top response. The FSR of the first grating is substantially equal to the channel spacing of the optical channels, such that the emission from the first grating achieves a cyclic offset of incidence angle into the second grating of the system.

Abstract: The invention relates to a planar lightwave circuit including a pair of opposed concave reflective diffraction gratings sharing the same focal line, which separates first and second slab waveguide regions. The ends of input and output waveguides are positioned along the focal line for launching and receiving light directed by one or both of the diffraction gratings. The invention enables light within in a certain wavelength range to be launched from an input waveguide, directed by a single diffraction grating, and output waveguides, all within a single slab waveguide region, while light within another wavelength range will be directed from one diffraction grating to another for output waveguides in a different slab waveguide region.