# US 5,345,326 A · Optical matrix switch

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- Number: US 5,345,326 A
- Document ID: US5345326A
- Status: Granted
- Kind: A
- Application number: 07/967,849
- Filed: 1992-10-28
- Granted: 1994-09-06
- Earliest claimed: 1991-10-28
- Assignees: NEC Corporation
- Inventors: Soichiro Araki
- Web page: https://patentgrep.com/patent/US5345326A

## CPC

- G02B 6/3556: {NxM switch, i.e. regular arrays of switches elements of matrix type constellation}
- G02F 1/015: based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction (G02F1/03 takes precedence)
- G02B 6/42: Coupling light guides with opto-electronic elements
- G02F 1/0126: {Opto-optical modulation, i.e. control of one light beam by another light beam, not otherwise provided for in this subclass}
- H01S 5/0608: {controlled by light, e.g. optical switch}
- H01S 5/183: having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

An optical matrix switch according to the present invention includes plural demultiplexing and multiplexing light paths, plural optical switching devices each provided on a corresponding one of the plural demultiplexing and multiplexing light paths. The optical switching devices are controlled to be selectively turned on and off.

## Claims

### Claim 1

An optical matrix switch, comprising:
plural input light paths, to which one or more input light signals are supplied;
plural output light paths, from which one or more output light signals are supplied to a following stage;
a plural demultiplexing and multiplexing light paths, each of aid plural demultiplexing and multiplexing light paths being coupled by a lattice pattern between a corresponding one of said plural input light paths and a corresponding one of said plural output light paths;
plural optical switching devices each provided on a corresponding one of said plural demultiplexing and multiplexing light paths; and
means for controlling said plural optical switching devices to be selectively turned on and off;
wherein one or more optical switching devices which are selectively turned on among said plural optical switching devices emit light signals to be supplied to one or more output light paths of said plural output light paths by receiving and amplifying one or more light signals from one or more input light paths of said plural input light paths, whereby the optical switching devices amplify only light signals having wavelengths assigned thereto; and
one or more optical switching devices which are selectively turned off among said plural optical switching devices emit no light signal by receiving and absorbing one or more light signals from one or more input light paths of said plural input light paths.

### Claim 2 (depends on 1)

An optical matrix switch, according to claim 1, wherein
each of said plural optical switching devices, comprises:
a semiconductor active layer having a predetermined bandgap energy for emitting light by current injected thereto;
semiconductor cladding layers for sandwiching said semiconductor active layer, said semiconductor cladding layers each having a bandgap energy greater than that of said semiconductor active layer, thereby providing a double-hereto structure; and
first and second pn layers provided on both surfaces of said double-hereto structure;
wherein said control means controls each of said one or more optical switching devices which are selectively turned on to be injected by said current which is lower in level than a threshold value.

### Claim 3 (depends on 2)

An optical matrix switch, according to claim 2, wherein:
said each of said plural optical switching devices, further comprises;
an n-mirror layer provided on said first pn layer; and
a p-mirror layer provided on said second pn layer.

### Claim 4 (depends on 1)

An optical matrix switch, according to claim 1, wherein:
said one or more light signals are light signals of different wave lengths; and
said one or more output light signals are wavelength division multiplexed lights of said different wavelengths.

### Claim 5 (depends on 4)

An optical matrix switch, according to claim 4, wherein:
said plural optical switching devices have different resonant wavelengths corresponding to said input light signals of said different wavelengths.