Jerry Z Chen

US Patent:

59265876, Jul 20, 1999

Filed:

Sep 8, 1997

Appl. No.:

8/925515

Inventors:

Jerry Chia-yung Chen - Keyport NJ
Corrado Dragone - Little Silver NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G02B 612

US Classification:

385 14

Abstract:

Two or more wavelength routers are cascaded together to form a passband filter with low levels of crosstalk between different channels of a wavelength division multiplexing (WDM) stream. Cascading wavelength routers is a technique that can be used to efficiently realize wide and flat passbands, but high levels of cross-talk may result from multi-path interference caused by grating lobes, which produce unwanted transmission paths between the two routers. Spatial filtering can be applied to inhibit the propagation of light-energy along the unwanted paths, and it can be implemented using any suitable techniques including pinholes, reflectors, waveguides, and multi-mode interferometers (MMIs). The resulting passband filter can be designed to generate levels of crosstalk similar to those of conventional passband filters that rely on a single waveguide router.

US Patent:

58899065, Mar 30, 1999

Filed:

May 28, 1997

Appl. No.:

8/864053

Inventors:

Jerry Chia-yung Chen - Keyport NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G02B 626
H04J 1400

US Classification:

385 28

Abstract:

A signal router includes a free space region with input and output sides. A number of input and output waveguide arms extend from the respective input and output sides of the free space region. At least a subset of the input or output waveguide arms are configured such that a signal applied to one of the waveguide arms excites multiple modes of that waveguide arm. Coupling between the multiple modes of the various waveguide arms is used to shape a multi-channel output radiation pattern of the router. The excitation of multiple modes may be provided by configuring a given waveguide arm to include a first portion and a second portion, with the second portion arranged between the first portion and a side of the free space region and having a width which is greater than a width of the first portion. Alternatively, the excitation of multiple modes may be provided by including one or more auxiliary waveguide arms between a given pair of main input or output waveguide arms. In either case, a desired multi-channel radiation pattern for a given router may be provided by altering characteristics of the waveguide arms.