Configurable optical add/drop device

Details Configurable optical add/drop device Configurable optical add/drop device

1999-03-24

2001-04-17

Lee, John D. (Department: 2874)

Optical waveguides

With optical coupler

Plural

C385S021000, C359S199200

Reexamination Certificate

active

06219474

ABSTRACT:

FIELD OF THE INVENTION
The invention relates to optical devices. More particularly, the invention relates to add/drop devices for optical communications networks.
BACKGROUND OF THE INVENTION
Fiber optic networks have the ability to communicate multiple channels of information on a single fiber. The ability to communicate multiple channels with a single fiber increases the bandwidth of networks and other devices including fiber optic networks as compared to communication channels that are limited to a single channel. Because each fiber can carry multiple channels, routing of channels is more complex than if each fiber carries a single channel.
One routing scheme is to route each channel to each device and allow the devices to access the appropriate information.
FIG. 1
is a block diagram of a simple network with each device having access to each channel of information. Network
100
includes devices
110
,
130
and
160
that are connected by fiber optic communications paths. Paths
120
and
125
communicate information between device
110
and device
130
. Similarly, paths
140
and
145
communicate information between device
130
and
160
, and paths
150
and
155
communicate information between device
110
and device
160
.
However, for networks having many devices, an interconnection between each device can be prohibitively expensive, or even physically impossible. In order to provide interconnection of many devices to a fiber optic network, add/drop devices have been developed.
FIG. 2
illustrates an add/drop device. Communications path
200
is a multi-channel fiber optic path that is optically coupled to drop filter
210
. Drop filter
210
filters a channel by passing the channel to communications path
220
and reflecting the remaining channels to communications path
230
. The channels passed to communications path
220
are delivered to device
240
that operates on the received channel.
Device
240
generates information that is communicated via path
250
to add filter
260
. Add filter
260
reflects the channels of path
230
and adds the channel of path
250
to provide a combination of channels to path
270
. In this manner device
240
is allowed to access to data on a channel without requiring access to all available channels.
However, the configuration of
FIG. 2
is static and must be determined at the time of network configuration. Adding and dropping additional channels requires physical addition of additional add and drop filters as well as splicing into multi-channel paths
200
and
270
. What is needed is an improved add/drop device.
SUMMARY OF THE INVENTION
An optical add/drop device is described. The add/drop device has an input port to receive multiple channels of information. A drop filter is optically coupled to the input port. The drop filter passes a channel or a group of channels and reflects the remaining channels to a first intermediate port. An add filter is optically coupled to a second intermediate port. The add filter combines the added channel or group of channels and reflects the remaining channels to an output port. A switch is optically coupled to the drop filter, to the add filter, to an add port and to a drop port. The switch selectively optically couples the drop filter to the drop port and the add port to the add filter when in a first state. The switch selectively optically couples the drop filter to the add filter and the add port to the drop port when in a second state. The basic add/drop function can be realized by optically linking the first and second intermediate ports. In one embodiment, the switch includes a diffraction prism to selectively optically couple the ports. In an alternative embodiment, the switch includes a mirror to selectively optically couple the ports of the add/drop device.
In one embodiment, multiple add/drop devices are interconnected to allow multiple channels or groups of channels to be dropped and added. The input ports, output ports, first intermediate ports, and second intermediate ports of the multiple add/drop devices are interconnected to allow dropping and adding of multiple channels.


REFERENCES:
patent: 5488500 (1996-01-01), Glance
patent: 5612805 (1997-03-01), Fevrier et al.
patent: 5712717 (1998-01-01), Hamel et al.
patent: 5712932 (1998-01-01), Alexander et al.
patent: 5748811 (1998-05-01), Amersfoort et al.
patent: 5771112 (1998-06-01), Hamel et al.
patent: 5778118 (1998-07-01), Sridhar
patent: 5822095 (1998-10-01), Taga et al.
patent: 5915051 (1999-06-01), Damask et al.
patent: 5940197 (1999-08-01), Ryu
patent: 5974207 (1999-10-01), Aksyuk et al.
patent: 6002503 (1999-12-01), Mizrahi
patent: 6035080 (2000-03-01), Henry et al.
patent: 6038045 (2000-03-01), Sotom et al.
patent: 6061157 (2000-05-01), Terahara
patent: 6061484 (2000-05-01), Jones et al.
patent: 6069719 (2000-05-01), Mizrahi
patent: 6084694 (2000-07-01), Milton et al.

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