Jds Uniphase Corporation

Lumentum Operations LLC

Hiroaki Yamada

Jyoti Kiron Bhardwaj

Barthelemy Fondeur

David J Dougherty

Zi-Wen Dong

Jinxi Shen

Robert Brainard

Sanjay M Thekdi

Anantharaman Vaidyanathan

David J Chapman

Thomas Nguyen

David K Nakamoto

Erik W Egan

Niranjan Gopinathan

Yingchao Yan

Suresh Ramalingam

Venkatesan Murali

Douglas E Crafts

Kenzo Ishida

James F Farrell

Steven M Swain

Jiamin Zheng

Mark Brian Farrelly

Yimin Hua

Shanrui Ren

Domenico Di Mola

In some implementations, a Mach-Zehnder interferometer (MZI) includes a delay line arm formed in a chip and a mirrored facet formed in the chip. The delay line arm may be configured to propagate light to the mirrored facet. The mirrored facet may be configured to reflect, to the delay line arm, a percentage of the light propagated to the mirrored facet by the delay line arm.

Mach-Zehnder interferometer with mirrored facet

An optical device may include a waveguide-based Mach-Zehnder (MZ) interferometer associated with performing polarization multiplexing or demultiplexing. The waveguide-based MZ interferomenter may include a first MZ arm, a second MZ arm, and a set of stress-balancing trenches. A portion of the first MZ arm may be between at least two stress-reducing trenches of a plurality of stress-reducing trenches. The plurality of stress-reducing trenches may be in a cladding layer on a substrate. The set of stress-balancing trenches may be on an opposite side of the second MZ arm from the plurality of stress-reducing trenches. The set of stress-balancing trenches may be in the cladding layer on the substrate.

Polarization multiplexer/demultiplexer with reduced polarization rotation

A spot size converter may include a tapered periodic segmented waveguide (PSW). The tapered PSW may include a plurality of waveguide segments defined by a plurality of gaps between the plurality of waveguide segments. The plurality of gaps may be at one or more angles that are not substantially parallel to a direction of a width of the tapered PSW. The direction of the width of the tapered PSW may be substantially perpendicular to a direction in which light passes through the tapered PSW.

Angled periodic segmented waveguide for spot size conversion with reduced return loss

An optical interferometer for demodulating a differential phase shift keying optical signal includes a planar lightwave circuit and at least one free space delay line optically coupled to the planar lightwave circuit. The planar lightwave circuit has a waveguide splitter, a waveguide coupler, and a phase adjuster. In operation, the splitter splits the optical signal into equal portions, the phase adjuster adjusts the relative phase of the optical signal portions, and the free space delay line provides one-bit delay between the portions of the optical signal. The delayed signals are mixed in the waveguide coupler. The free space delay line can be made variable for adjustment of the bit delay for operation at different bit rates, and/or for optimization of the interferometer performance.

Optical interferometer

An optical device for rearranging wavelength channels in an optical network is disclosed. The optical device has a wavelength selective coupler having one input port and a plurality of output ports coupled to a plurality of input ports of an optical grating demultiplexor such as an arrayed waveguide grating. The wavelength channels in each of the input ports are dispersed by the demultiplexor and are directed to a plurality of output ports of the optical grating demultiplexor. As a result, at least one wavelength channel at each of the input ports of the optical grating demultiplexor is coupled into a common output port. The optical device is useful in passive optical networks wherein a same demultiplexor is used for simultaneous multiplexing and demultiplexing of wavelength channels.

Optical device for rearranging wavelength channels

A planar lightwave circuit generalized for handling any given band of multiple bands of a wavelength range, including a first grating element handling a first group of bands; and a second grating element handling a second group of bands. The first and second groups of bands overlap in the wavelength range, and may be spaced apart by a fixed wavelength value. By providing two periodic grating elements handling alternating bands, their free spectral range is allowed to expand, improving their roll-off characteristics. By providing separate inputs for each band, wavelength accuracy can be improved. Device flexibility can be further improved by using switch and interleaver fabrics at the inputs and outputs. The resultant device, generalized to handle any given band within a wavelength range, eliminates the need for separate component design and inventory tracking otherwise necessary.

Multi-band arrayed waveguide grating with improved insertion loss and wavelength accuracy

A planar lightwave circuit includes at least one optical waveguide core, and at least one feature proximate the core having a stress-engineered property to balance stress and therefore minimize birefringence affecting the core. A protective passivation layer is formed over the core and the feature to be substantially non-interfering with the balanced stress provided by the feature. The stress balancing feature may be an overcladding layer formed over the core, doped to have a coefficient of thermal expansion approximately matched to that of an underlying substrate, to symmetrically distribute stress in an undercladding between the overcladding and the substrate, away from the core. The protective passivation layer is formed to have a coefficient of thermal expansion approximately matched to that of the overcladding. In one exemplary embodiment, the passivation layer is formed from silicon nitride. Related concepts of stress release grooves, and core overetching, are also disclosed.

Waveguide stress engineering and compatible passivation in planar lightwave circuits

A planar lightwave circuit includes an arrayed waveguide grating (AWG), with input and output waveguides, partially curved array waveguides with respective length differences, and planar waveguide regions for focusing optical energy between the input/output and array waveguides. Optimal waveguide widths and spacing along the planar waveguide region facets are disclosed, which are largely determinative of AWG size and optical performance. Also disclosed are optimal cross-sectional waveguide dimensions (e.g., width and height); modified index of refraction difference between the waveguide core and cladding regions; and optimal array waveguide lengths, path length differences, and free spectral range. These features, especially when combined with advanced fiber attachment, passivation and packaging techniques, result in high-yield, high-performance AWGs (both gaussian and flattop versions).

Compact, low insertion loss, high yield arrayed waveguide grating

Growing community of inventors

San Jose, CA, United States of America

Hiroaki Yamada