(19)
(11)EP 0 278 450 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
30.11.1994 Bulletin 1994/48

(21)Application number: 88101787.5

(22)Date of filing:  08.02.1988
(51)International Patent Classification (IPC)5H04Q 3/52, H04B 10/00, H04J 14/00, G02F 1/29

(54)

An optical matrix switch

Optischer Matrixschalter

Commutateur optique sous forme de matrice


(84)Designated Contracting States:
DE FR GB SE

(30)Priority: 10.02.1987 JP 30180/87 U

(43)Date of publication of application:
17.08.1988 Bulletin 1988/33

(73)Proprietor: NEC CORPORATION
Tokyo (JP)

(72)Inventor:
  • Suzuki, Syuji c/o NEC Corporation
    Minato-ku Tokyo (JP)

(74)Representative: VOSSIUS & PARTNER 
Postfach 86 07 67
81634 München
81634 München (DE)


(56)References cited: : 
  
  • PHILIPS JOURNAL OF RESEARCH, vol. 41, no, 6, 1986, pages 507-530, Eindhoven,NL; P.J. SEVERIN: "Self-routing fibre-optic networks and switches using multi-tailed receiver/transmitter units"
  • IEEE JOURNAL OF QUANTUM ELECTRONICS, vol. QE-22, no. 6, June 1986, pages 964-967, IEEE, New York, US; R.A. SPANKE: "Architectures for large nonblockingoptical space switches"
  • IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, Atlanta, Georgia, 26th-29th November1984, vol. 1, paper 5.1, pages 105-113, IEEE, New York, US; R.J. McMILLEN: "A survey of interconnection networks"
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description


[0001] The invention relates to an optical matrix switch, and more particularly to an optical matrix switch through which an optical output signal from one of input optical fibers is supplied to a selected one of output optical fibers.

[0002] An optical matrix switch is applied to an optical communication network in which a large quantity of data are transmitted through optical fibers in a high speed whereby an optical output signal from one of input optical fibers each connected to the optical matrix switch can be supplied to a selected one of output optical fibers also connected to the optical matrix switch.

[0003] One of conventional optical matrix switches is described in the Optical Fiber Communication Conference Technical Digest WB2 published on Jan. 19, 1987. The optical matrix switch comprises a plural rows of optical switch elements dependent upon the respective number of input and output fibers to be connected thereto. Each of the optical switch elements is provided with two inputs and two outputs wherein an optical signal of one of the two inputs can be supplied from any one of the two outputs so that an optical switching operation is realized. The construction and operation of the optical matrix switch will be described in detail later.

[0004] According to the conventional optical matrix switch, however, a size thereof is inevitably large in its longitudinal direction. For instance, where the optical matrix switch is provided with four inputs and four outputs to be called "4 x 4 optical matrix switch", four rows of optical switch elements must be included therein. Therefore, the longitudinal length can not be less than a length as much as four times the longitudinal dimension of an optical switch element.

[0005] As a result, a substrate on which the four rows of the optical switch elements are provided must be large in its surface area thereby to increase a fabricating cost thereof.
Philips Journal of Research vol. 41, no. 6, 1986, pages 507-530, Eindhoven, NL; P.J. SEVERIN: "Self-routing fibre-optic networks and switches using multi-tailed receiver/transmitter units" discloses self-routing fibre-optic networks and switches using multi-tailed receiver/transmitter units. Each multi-tailed unit consists of a PIN diode and a LED source, with a simple circuit in-between, an N coupler input and an N splitter output. Some network configurations comprising a plurality of multi-tailed stations (MTS) are described. The patterns of some of the switches disclosed therein are blocking 4 x 4 and 8 x 8 optical switches and others are combined by optical dividers and optical switch elements.

[0006] Accordingly, it is an object of the invention to provide an optical matrix switch in which a size thereof can be smaller in its longitudinal direction.

[0007] It is a further object of the invention to provide an optical matrix switch in which a substrate for providing a plurality of rows of optical switch elements thereon can be smaller to avoid the increase of a fabricating cost thereof.

[0008] According to the invention, an optical matrix switch comprises the features of claim 1 and 3, respectively.

[0009] In other words, in the optical matrix switch according to claim 1
   said outputs of M/2 in number in each of said 1 x M/2 optical switch means of N in number are respectively connected to said optical switch elements of M/2 in number of a corresponding group among said optical switch groups of N/2 in number, and said inputs of N/2 in number in each of said N/2 x 1 optical switch means of M in number are respectively connected to optical switch elements each selected from each of said optical switch groups of N/2 in number whereby an optical signal supplied to any one of said inputs of N in number is switched to be appeared at a predetermined one of said outputs of M in number by selecting a predetermined one of optical signal transmitting paths formed through said optical switch groups of N/2 in number between said 1 x M/2 optical switch means of N in number and said N/2 x 1 optical switch means of M in number in accordance with "BAR" and/or "CROSS" states of corresponding optical switch elements therein.

[0010] The invention will be described in more detail in conjunction with drawings wherein,

Fig. 1 is an explanatory diagram showing a conventional optical matrix switch,

Fig. 2 is an explanatory diagram showing an optical switch element used in the conventional optical matrix switch in Fig. 1,

Figs. 3A and 3B are explanatory charts showing switching properties of the optical switch element in Fig. 2, and

Figs. 4 and 5 are explanatory diagrams showing first and second embodiments according to the invention.



[0011] Before explaining an embodiment according to the invention, the aforementioned conventional optical matrix switch will be described in conjunction with Fig. 1 in which a 4 x 4 optical matrix switch is shown. The 4 x 4 optical matrix switch comprises four rows of optical switch elements 21 to 24, 31 to 34, 41 to 44, and 51 to 54 respectively provided on a substrate 100 and connected through optical waveguides grown thereon. The substrate 100 is provided with four inputs 11 to 14 and four outputs 61 to 64 on both end planes thereof.

[0012] Fig. 2 shows one of the optical switch elements which comprises two optical waveguides 205 and 206 grown to be adjacent to each other on an optical crystal substrate 200 having a electro optic effect, and electrodes 207 and 208 to one of which a voltage V is applied through a terminal 209 and the remaining one of which is connected to the ground wherein the respective terminals of the optical waveguides 205 and 206 are used to be inputs 201 and 202, and outputs 203 and 204.

[0013] Fig. 3A shows Pout 1 which is an optical signal at the output 203 in regard to Pin 1 and Pin 2 which are optical signals at the inputs 201 and 202 in a case where a voltage V is applied to be controlled from Vl to Vh to the terminal 209 of the electrode 207, while Fig. 3B shows Pout 2 which is an optical signal at the output 204 in regard to the Pin 1 and Pin 2 in a case where the voltage V is applied thereto. As clearly understood from Figs. 3A and 3B, the Pin 1 is obtained to be as the Pout 1 at the output 203, and the Pin 2 is obtained to be as the Pout 2 at the output 204 when the voltage Vl is applied to the terminal 209 of the electrode 207, while the Pin 2 is obtained to be as the Pout 1 at the output 203, and the Pin 1 is obtained to be as the Pout 2 at the output 204 when the voltage Vh is applied thereto. In the optical switch element, the former is called "BAR state", while the latter is called "CROSS state".

[0014] In operation of the optical matrix switch as shown in Fig. 1, an optical signal is switched from the input 11 to the output 63 as indicated by a thick solid line when the optical switch element 32 is controlled to be "CROSS state", and the optical switch elements 21, 44 and 53 are controlled to be "BAR state". Further, an optical signal is switched from the input 12 to the output 64 as also indicated by a thick solid line when the optical switch elements 44 and 54 are controlled to be "BAR state", and the optical switch elements 22 and 34 are controlled to be "CROSS state". In this manner, optical signals can be switched among input and output fibers respectively coupled to the inputs 11 to 14 and outputs 61 to 64 of the optical matrix switch.

[0015] As clearly understood from the illustration in Fig. 1, the optical matrix switch is large in its size of the longitudinal direction as explained before.

[0016] In Fig. 4, there is shown an optical matrix switch in a first embodiment according to the invention. This is an optical matrix switch which is adapted to an N x M optical matrix switch having inputs of N and outputs of M respectively in number, and comprises 1 x M/2 optical switch means 421 to 428 of N in number each including, for instance, optical switch elements 421A, 421B and 421C to have one input and ouputs of M/2 in number (the remaining input of the optical switch element 421A is idle, not specifically explained hereinafter), optical switch groups 431 to 434 of N/2 in number each including, for instance, optical switch elements 431A, 431B, 431C and 431D of M/2 in number, N/2 x 1 optical switch means 441 to 448 of M in number each including, for instance, optical switch elements 441A, 441B and 441C to have inputs of N/2 in number and one output(the remaining one output is idle), and a substrate 400 for providing the 1 x M/2 optical switch means 421 to 428, optical switch groups 431 to 434, and N/2 x 1 optical switch means 441 to 448 thereon. The substrate 400 is provided thereon with inputs 411 to 418 of N in number connected to the respective inputs of the 1 x M/2 optical switch means 421 to 428, and outputs 451 to 458 of M in number connected to the respective outputs of the N/2 x 1 optical switch means 441 to 448. The respective outputs of M/2 in number of the 1 x M/2 optical switch means 421 and 422 are connected to a corresponding one of the optical switch elements 431A, 431B, 431C, and 431D of M/2 in number of the first optical switch group 431. In the same manner, the respective outputs of the remaining 1 x M/2 optical switch means 423 to 428 are connected to the remaining N/2 optical switch groups 432 to 434, although repeated explanations are omitted for simplification here. Further, each of the respective inputs of N/2 in number of the N/2 x 1 optical switch means 441 are connected to a corresponding one of the respective ouputs of the optical switch groups 431 to 434. In the same manner, the outputs of the remaining N/2 x 1 optical switch means 442 to 448 are correspondingly connected to the outputs of the optical switch groups 431 to 434.

[0017] In operation, an optical signal supplied to the input 411 is switched to be appeared at the output 451 as follows. For this purpose, the optical switch elements 421A and 421B in the 1 x M/2 optical switch means 421 are controlled to be "BAR state" and "CROSS state" respectively so that the optical signal is transmitted from the input 411 to the optical switch element 431A of the first optical switch group 431. Further, the optical switch element 431A, and the optical switch elements 441A and 441C in the N/2 x 1 optical switch means 441 are controlled to be "BAR state", "CROSS state", and "BAR state" respectively whereby the optical signal is supplied from the optical switch element 431A to the output 451. On the other hand, if the optical switch element 431A, and the two corresponding optical switch elements 442A and 442C of the N/2 x 1 optical switch means 442 are controlled to be "CROSS state", "CROSS state", and "BAR state" respectively, the optical signal supplied to the input 411 is switched to be appeared at the output 452.

[0018] The other switching examples are explained in a table as shown below where the corresponding optical switch elements are controlled as in the table.



[0019] In this manner, an optical signal supplied to any one of the inputs 401 to 418 can be switched to be appeared at a predetermined one of the outputs 451 to 458.

[0020] Considering a size of the optical matrix switch as shown in Fig. 4, the optical switch elements are longitudinally arranged in the 1 x M/2 optical switch means 421 to 428 by log₂M/2 in number. In the embodiment, two rows of the optical switch elements 421A and 421B (or 421A and 421C) are arranged, for instance, in the 1 x M/2 optical switch means 421 because the number "M" is assumed to be "8". For the same reason, two rows of the optical switch elements 441A and 441C (or 441B and 441C) are arranged, for instance, in the N/2 x 1 optical switch means 441 because the number "N" is "8". On the other hand, a single row of the optical switch elements 431A, 431B ------ are transversely arranged in the optical switch groups 431 to 434. Therefore, the 8 x 8 optical matrix switch as shown in Fig. 4 is of a size in which five rows of the optical switch elements are longitudinally arranged thereby making it smaller even than the conventional 4 x 4 optical matrix switch including seven rows of the optical switch elements as shown in Fig. 1. In general, an optical matrix switch of the invention is made smaller to be of a size in which optical switch elements of (log₂M/2 + 1 + log₂N/2) in number are longitudinally arranged.

[0021] In Fig. 5, there is shown an optical matrix switch in a second embodiment according to the invention which is of a 4 x 4 optical matrix switch. The optical matrix switch comprises 1 x 2 optical switch means 521 to 524 each being of an optical switch element having two input and two outputs, two optical switch groups 531 and 532 each including two optical switch elements 531A and 531B, and 532A and 532B respectively, 2 x 1 optical switch means 541 to 544 each being of an optical switch element having two inputs and one output, and a substrate 500 for providing the respective optical switch elements thereon and which is provided on the both end planes with four inputs 511 to 514 connected to the 1 x 2 optical switch means 521 to 524, and four outputs 551 to 554 connected to the 2 x 1 optical switch means 541 to 544. The first and second outputs of the 1 x 2 optical switch means 521 are connected to the first inputs of the optical switch elements 531A and 531B in the first optical switch group 531 respectively, while the first and second outputs of 1 x 2 optical switch means 522 are connected to the second inputs thereof respectively. In the same manner, the first and second outputs of the 1 x 2 optical switch means 523, and those of the 1 x 2 optical switch means 524 are connected to the first inputs of the optical switch elements 532A and 532B in the second optical switch groups 532, and to the second inputs thereof respectively. Further, the first and second outputs of the optical switch element 531A are connected to the first inputs of the 2 x 1 optical switch means 541 and 542 respectively, and the first and second outputs of the optical switch element 531B are connected to the first inputs of the 2 x 1 optical switch means 543 and 544 respectively. In the same manner, the respective first and second outputs of the optical switch elements 532A and 532B are connected to the second inputs of the 2 x 1 optical switch means 541 to 544 respectively.

[0022] In operation, where the 1 x 2 optical switch means 521, optical switch element 531A and 2 x 1 optical switch means 541 are all controlled to be "BAR state", an optical signal supplied to the input 511 is switched to be appeared at the output 551. Similarly, where the 1 x 2 optical switch means 521, optical switch element 531A and 2 x 1 optical switch means 541 are controlled to be "BAR state", "CROSS state", and "BAR state" respectively, an optical signal is switched from the input 511 to the output 552. On the other hand, an optical signal is switched from the input 511 to the output 552 in a case where the 1 x 2 optical switch means 521, optical switch element 531B and 2 x 1 optical switch means 543 are controlled to be "CROSS state", "BAR state", and "BAR state" respectively, while an optical signal supplied to the input 511 is switched to the output 554 in a case where the 1 x 2 optical switch means 521, optical switch element 531B and optical switch means 544 are controlled to be "CROSS state", "CROSS state", and "BAR state" respectively.

[0023] As clearly understood from the illustration in Fig. 5, the longitudinal length of the 4 x 4 optical matrix switch is slightly larger than a dimension as small as three times a length of an optical switch element. As a result, that of the 4 x 4 optical matrix switch becomes less than the conventional 4 x 4 optical matrix switch as shown in Fig. 1.


Claims

1. An optical matrix switch comprising,
   inputs of N in number where N is an integer,
   outputs of M in number where M is an integer,
   1 x M/2 optical switch means (421-428; 521-524) of N in number each including a predetermined number of optical switch elements (421A, 421B, 421C) and having a single input connected to a corresponding one of said inputs of N in number, and having outputs of M/2 in number,
   optical switch groups (431-434; 531, 532) of N/2 in number, each of said optical switch groups including optical switch elements (431A, 431B, 431C, 431D; 531A, 531B) of M/2 in number, each of said optical switch elements being of a 2 x 2 optical switch element having two inputs and two outputs, and
   N/2 x 1 optical switch means (441-448; 541-544) of M in number each including a predetermined number of optical switch elements (441A, 441B, 441C) and having a single output connected to a corresponding one of said outputs of M in number, and having inputs of N/2 in number,
wherein the j-th output (1≦j≦M/2) of the i-th 1×M/2 optical switch means (1≦i≦N) is connected to the first input of the j-th optical switch element in the (i+1)/2-th optical switch group, when i is an odd number, and to the second input of the j-th optical switch element in the i/2-th optical switch group, when i is an even number, and the l-th input (1≦l≦N/2) of the k-th N/2×1 optical switch means (l≦k≦M) is connected to the first output of the (k+1)/2-th optical switch element in the l-th optical switch group, when k is an odd number, and to the second output of the k/2-th optical switch element in the l-th optical switch group, when k is an even number.
 
2. An optical matrix switch according to claim 1,
   wherein said predetermined number of optical switch elements in each of said 1 x M/2 optical switch means (421-428; 521-524) of N in number is decided dependent upon a number of optical switch elements arranged in the longitudinal direction which is defined by an equation of log₂M/2, and said predetermined number of optical switch elements in each of said N/2 x 1 optical switch means (441-448; 541-544) of M in number is decided in the same manner as above by an equation of log₂N/2.
 
3. An optical matrix switch comprising,
   four inputs and four outputs respectively provided on both end planes of a substrate (500),
   four 1 x 2 optical switch elements (511-514) provided on said substrate (500) each having one input connected to a corresponding one of said four inputs, and having two outputs,
   two optical switch groups (531, 532) provided on said substrate each including two 2 x 2 optical switch elements (531A, 531B) each having two inputs and two outputs, and
   four 2 x 1 optical switch elements (541-544) provided on said substrate each having two inputs, and having one output connected to a corresponding one of said four outputs,
wherein the i-th output (i= 1 or 2) of the first 1x2 optical switch element (521) is connected to the first input of the i-th optical switch element in the first optical switch group (531), the j-th output (j= 1 or 2) of the second 1x2 optical switch element (522) is connected to the second input of the j-th optical switch element in the first optical switch group (531), the k-th output (k= 1 or 2) of the third 1x2 optical switch element (523) is connected to the first input of the k-th optical switch element in the second optical switch group (532), the l-th output (l= 1 or 2) of the fourth 1x2 optical switch element (524) is connected to the second input of the l-th optical switch element in the second optical switch group (532), the m-th input (m= 1 or 2) of the first 2x1 optical switch element (541) is connected to the first output of the first optical switch element (531A, 532A) in the m-th optical switch group, the n-th input (n= 1 or 2) of the second 2x1 optical switch element (542) is connected to the second output of the first optical switch element (531A, 532A) in the n-th optical switch group, the o-th input (o= 1 or 2) of the third 2x1 optical switch element (543) is connected to the first output of the second optical switch element (531B, 532B) of the o-th optical switch group, and the p-th input (p= 1 or 2) of the fourth 2x1 optical switch element (544) is connected to the second output of the second optical switch element (531B, 532B) in the p-th optical switch group.
 
4. An optical matrix switch according to claim 3,
   wherein each of said four 1 x 2 optical switch elements (521-524) and of said four 2 x 1 optical switch elements (541-544) is of a 2 x 2 optical switch element having two input and two outputs, and
   one of said two inputs being idle for each of said four 1 x 2 optical switch elements (521-524), and one of said two outputs being idle for each of said four 2 x 1 optical switch elements (541-544).
 


Ansprüche

1. Optischer Matrixschalter mit:
   einer Anzahl von N Eingängen, wobei N eine ganze Zahl ist,
   einer Anzahl von M Ausgängen, wobei M eine ganze Zahl ist,
   einer Anzahl von N optischen (1 x M/2)-Schalteinrichtungen (421-428;521-524), von denen jede eine vorgegebene Anzahl optischer Schaltelemente (421A,421B,421C) und einen einzigen Eingang, der mit einem entsprechenden der Eingänge der Anzahl N verbunden ist, und eine Anzahl von M/2 Ausgängen aufweist,
   einer Anzahl von N/2 optischen Schaltgruppen (431-434;531,532), wobei jede optische Schaltgruppe eine Anzahl von M/2 optischen Schaltelementen (431A,431B,431C,431D;531A,531B) umfaßt, wobei jedes optische Schaltelement ein optisches (2 x 2)-Schaltelement mit zwei Eingängen und zwei Ausgängen ist, und
   einer Anzahl von M optischen (N/2 x 1)-Schalteinrichtungen (441-448;541-544), von denen jede eine vorgegebene Anzahl von optischen Schaltelementen (441A,441B,441C) und einen einzigen Ausgang, der mit einem entsprechenden der Ausgänge der Anzahl M verbunden ist, und eine Anzahl von N/2 Eingängen aufweist,
   bei dem der j-te Ausgang (1≦j≦M/2) der i-ten optischen (1 x M/2)- Schalteinrichtung (1≦i≦N) mit dem ersten Eingang des j-ten optischen Schaltelements in der (i+1)/2-ten optischen Schaltgruppe verbunden ist, wenn i eine ungerade Zahl ist, und mit dem zweiten Eingang des j-ten optischen Schaltelements in der i/2-ten optischen Schaltgruppe verbunden ist, wenn i eine gerade Zahl ist, und der l-te Eingang (1≦l≦N/2) der k-ten optischen (N/2 x 1)- Schalteinrichtung (1≦k≦M) mit dem ersten Ausgang des (k+1)/2-ten optischen Schaltelements in der l-ten optischen Schaltgruppe verbunden ist, wenn k eine ungerade Zahl ist, und mit dem zweiten Ausgang des k/2-ten optischen Schaltelements in der l-ten optischen Schaltgruppe verbunden ist, wenn k eine gerade Zahl ist.
 
2. Optischer Matrixschalter nach Anspruch 1,
   bei dem die vorgegebene Anzahl optischer Schaltelemente in jeder der optischen (1 x M/2)-Schalteinrichtungen (421-428;521-524) der Anzahl N abhängig von der Anzahl der in Längsrichtung angeordneten optischen Schaltelemente bestimmt wird, die sich aus einer Gleichung von log₂M/2 ergibt, und die vorgegebene Anzahl optischer Schaltelemente in jeder der optischen (N/2 x 1)-Schalteinrichtungen (441-448;541-544) der Anzahl M sich in gleicher Weise wie oben aus einer Gleichung von log₂N/2 bestimmt wird.
 
3. Optischer Matrixschalter mit:
   vier Eingängen und vier Ausgängen, die jeweils an den beiden Endflächen eines Substrats (500) vorgesehen sind,
   vier auf dem Substrat (500) vorgesehenen optischen (1 x 2)-Schaltelementen (511-514), wobei jedes einen Eingang, der mit einem entsprechenden der vier Eingänge verbunden ist, und zwei Ausgänge hat,
   zwei auf dem Substrat vorgesehenen optischen Schaltgruppen (531,532), wobei jede zwei optische (2 x 2)-Schaltelemente (531A,531B) mit jeweils zwei Eingängen und zwei Ausgänge umfaßt,
   vier auf dem Substrat vorgesehenen optischen (2 x 1)-Schaltelementen (541-544), wobei jedes zwei Eingänge und einen Ausgang hat, der mit einem entsprechenden der vier Ausgänge verbundenen ist,
   bei dem der i-te Ausgang (i= 1 oder 2) des ersten optischen (1 x 2)-Schaltelements (521) mit dem ersten Eingang des i-ten optischen Schaltelements in der ersten optischen Schaltgruppe (531) verbunden ist, der j-te Ausgang (j= 1 oder 2) des zweiten optischen (1 x 2)-Schaltelements (522) mit dem zweiten Eingang des j-ten optischen Schaltelements in der ersten optischen Schaltgruppe (531) verbunden ist, der k-te Ausgang (k= 1 oder 2) des dritten optischen (1 x 2)-Schaltelements (523) mit dem ersten Eingang des k-ten optischen Schaltelements in der zweiten optischen Schaltgruppe (532) verbunden ist, der l-te Ausgang (l= 1 oder 2) des vierten optischen (1 x 2)-Schaltelements (524) mit dem zweiten Eingang des l-ten optischen Schaltelements in der zweiten optischen Schaltgruppe (532) verbunden ist, der m-te Eingang (m= 1 oder 2) des ersten optischen (2 x 1)-Schaltelements (541) mit dem ersten Ausgang des ersten optischen Schaltelements (531A,532A) in der m-ten optischen Schaltgruppe verbunden ist, der n-te Eingang (n= 1 oder 2) des zweiten optischen (2 x 1)-Schaltelements (542) mit dem zweiten Ausgang des ersten optischen Schaltelements (531A,532A) in der n-ten optischen Schaltgruppe verbunden ist, der o-te Eingang (o= 1 oder 2) des dritten optischen (2 x 1)-Schaltelements (543) mit dem ersten Ausgang des zweiten optischen Schaltelements (531B,532B) der o-ten optischen Schaltgruppe verbunden ist und der p-te Eingang (p= 1 oder 2) des vierten optischen (2 x 1)-Schaltelements (544) mit dem zweiten Ausgang des zweiten optischen Schaltelements (531B,532B) in der p-ten optischen Schaltgruppe verbunden ist.
 
4. Optischer Matrixschalter nach Anspruch 3,
   bei dem jedes der vier optischen (1 x 2)-Schaltelemente (521-524) und der vier optischen (2 x 1)-Schaltelemente (541-544) ein optisches (2 x 2)-Schaltelement mit zwei Eingängen und zwei Ausgängen ist, und
   einer der zwei Eingänge für jeden der vier optischen (1 x 2)-Schaltelemente (521-524) nicht belegt ist und einer der zwei Ausgänge für jeden der vier optischen (2 x 1 )-Schaltelemente (541-544) nicht belegt ist.
 


Revendications

1. Commutateur matriciel optique comprenant,
   des entrées d'un nombre N où N est un nombre entier,
   des sorties d'un nombre M où M est un nombre entier,
   des moyens de commutation optique 1 x M/2 (421 à 428, 521 à 524) d'un nombre égal à N chacun comportant un nombre prédéterminé d'éléments de commutation optique (421A, 421B, 421C) et ayant une seule entrée connectée à une entrée correspondante parmi lesdites entrées de nombre N et ayant des sorties d'un nombre égal à M/2,
   des groupes de commutateurs optiques (431 à 434, 531, 532) d'un nombre égal à N/2, chacun desdits groupes de commutateurs optiques comportant des éléments de commutation optique (431A, 431B, 431C, 431D, 531A, 531B) d'un nombre égal à M/2, chacun desdits éléments de commutation optique étant un élément de commutation optique 2 x 2 ayant deux entrées et deux sorties, et
   des moyens de commutation optique N/2 x 1 (441 à 448, 541 à 544) d'un nombre égal à M chacun comportant un nombre prédéterminé d'éléments de commutation optique (441A, 441B, 441C) et ayant une seule sortie connectée à une sortie correspondante parmi lesdites sorties de nombre M et ayant des entrées d'un nombre égal à N/2,
   dans lequel la jième sortie (1≦j≦M/2) du iième moyen de commutation optique 1 x M/2 (1≦i≦N) est connectée à la première entrée du jième élément de commutation optique dans le (i+1)/2ième groupe de commutateur optique, lorsque i est un nombre impair, à la seconde entrée du jième élément de commutation optique dans le i/2ième groupe de commutateurs optiques, lorsque i est un nombre pair et la lième entrée (1≦l≦N/2) du kième moyen de commutateur optique N/2 x 1 (1≦k≦M) est connectée à la première sortie du (k + 1)/2ième élément de commutation optique dans le lième groupe de commutateurs optiques, lorsque k est un nombre impair et à la seconde sortie du k/2ième élément de commutation optique dans le lième groupe de commutateurs optiques, lorsque k est un nombre pair.
 
2. Commutateur matriciel optique selon la revendication 1,
   dans lequel ledit nombre prédéterminé d'éléments de commutation optique dans chacun desdits moyens de commutation optique 1 M/2 (421 à 428, 521 à 524) de nombre N est choisi dépendant du nombre d'éléments de commutation optique disposés dans la direction longitudinale qui est défini par une équation de log₂M/2 et ledit nombre prédéterminé d'éléments de commutation optique dans chacun desdits moyens de commutation optique N/2 x 1 (441 à 448, 541 à 544) de nombre M est choisi de la même manière que ci-dessus par une équation de log₂N/2.
 
3. Commutateur matriciel optique comprenant,
   quatre entrées et quatre sorties respectivement prévues sur les deux plans d'extrémités d'un substrat (500),
   quatre éléments de commutation optique 1 x 2 (511 à 514) prévus sur lesdits substrats (500) chacun ayant une entrée connectée à une sortie correspondante parmi lesdites quatre entrées et ayant deux sorties,
   deux groupes de commutateurs optiques (531, 532) prévus sur lesdits substrats comportant chacun deux éléments de commutation optique 2 x 2 (531A, 531B) ayant chacun deux entrées et deux sorties, et
   quatre éléments de commutation optique 2 x 1 (541 à 544) prévus sur ledit substrat ayant chacun deux entrées et ayant une sortie connectée à une sortie correspondante parmi lesdites quatre sorties,
   dans lequel la iième sortie (i = 1 ou 2) du premier élément de commutation optique 1 x 2 (521) est connectée à la première entrée du iième élément de commutation optique dans le premier groupe de commutateurs optiques (531), la jième sortie ( j = 1 ou 2) du second élément de commutation optique 1 x 2 (522) est connectée à la seconde entrée du jième élément de commutation optique dans le premier groupe de commutateur optique (531), la kième sortie (k = 1 ou 2) du troisième élément de commutation optique 1 x 2 (523) est connectée à la première entrée du kième élément de commutation optique dans le second groupe de commutateurs optiques (532), la lième sortie (l = 1 ou 2) du quatrième élément de commutation optique 1 x 2 (524) est connectée à la seconde entrée du lième élément de commutation optique dans le second groupe de commutateurs optiques (532), la mième entrée (m = 1 ou 2) du premier élément de commutation optique 2 x 1 (541) est connectée à la première sortie du premier élément de commutation optique (531A, 532A) dans le mième groupe de commutateurs optiques, la nième entrée (n = 1 ou 2) du second élément de commutation optique 2 x 1 (542) est connectée à la seconde sortie du premier élément de commutation optique (531A, 532A) dans le nième groupe de commutateurs optiques, la oième entrée (o = 1 ou 2) du troisième élément de commutation optique 2 x 1 (543) est connectée à la première sortie du second élément de commutation optique (531B, 532B) du oième groupe de commutateurs optiques et la pième entrée ( p = 1 ou 2) du quatrième élément de commutation optique 2 x 1 (544) est connectée à la seconde sortie du second élément de commutation optique (531B, 532B) dans le pième groupe de commutateurs optiques.
 
4. Commutateur matriciel optique selon la revendication 3,
   dans lequel chacun desdits quatre éléments de commutation optique 1 x 2 (521 à 524) et desdits quatre éléments de commutation optique 2 x 1 (541 à 544) est constitué d'un élément de commutation optique 2 x 2 ayant deux entrées et deux sorties, et
   une desdites deux entrées étant libre pour chacun desdits quatre éléments de commutation optique 1 x 2 (521 à 524) et une desdites deux sorties étant libre pour chacun desdits quatre éléments de commutation optique 2 x 1 (541 à 544).
 




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