Abstract:
A system and method of utilizing spherical and hemispherical shaped devices to function as an optical switch is disclosed. The optical switch can contain mirrors that turn on and off, or are fixed in place with a movable spherical device. Additionally, the optical switches can contain grating patterns to deflect an optical signal from its original path. The grating patterns can vary in design and pattern to deflect the optical signal in almost any direction, or to not let the optical signal continue. The optical switch can also include photo sensors along the exterior of the sphere or along the reflection device. The optical switch can also include an integrated circuits.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an optical switch having an optical transmission path with an optical transmission medium, a radiation source associated with an input-side end of the optical transmission path for emitting a primary optical signal being coupled into the transmission path, and a optical switch between the input-side and an output-side end of the transmission path. 
     CROSS REFERENCE 
     U.S. patent application Ser. No. 09/557,654, filed herewith, entitled “System and Method for Refracting and Deflecting Light Utilizing Liquid Crystal Bars and Blocks” is hereby incorporated by reference as if reproduced in its entirety. 
     In U.S. Pat. No. 5,955,776, assigned to the same assignee as the present application and hereby incorporated by reference as if reproduced in its entirety, a method and system for manufacturing spherical-shaped semiconductor integrated circuits is disclosed. A manufacturing process disclosed in the aforementioned patent is used to create and process semiconductor spheres, such as may be used for spherical-shaped semiconductor integrated circuits. 
     In U.S. patent application Ser. No. 09/483,640, filed on Jan. 14, 2000, assigned to the same assignee as the present application and hereby incorporated by reference as if reproduced in its entirety, a method of making small gaps for small electrical/mechanical devices is disclosed. 
     BACKGROUND OF THE INVENTION 
     Known optical switches use two fiberoptical waveguides, specifically one fiber for an outgoing path and one fiber for a return path of the optical signal. In the switching operation, as a rule, the location of a suitably constructed reflector is changed in such a way that either it couples the light signal from one fiber into the other fiber, or it interrupts an already existing coupling of the light signal and/or redirects it into another fiber. 
     FIG. 1 shows a first prism  50  glued together with optical glue to a second prism  52 . The optical glue forms a mirror  54  that reflects an incoming signal  56  into an outgoing signal path  58 . 
     FIG. 2 shows the same first prism  50  attached to the same second prism  52 , but this embodiment does not have the mirror found in FIG.  1 . Therefore, as the incoming signal  56  goes through the first prism  50 , the signal does not get reflected, but passes through the second prism  52  into the second outgoing signal  60 . 
     Although other embodiments exist for optical switches and many different methods exist to turn on and off the mirror between the two prisms, FIGS. 1 and 2 show the basic concepts of optical switching. 
     However, the current optical switches and methods have much room for improvement in cost, size and speed in order to enable the optical networks of the future. 
     Another technology explores the conventional concepts of integrated circuits, or “chips”. Chips are usually formed from a flat surface semiconductor wafer. The semiconductor wafer is first manufactured in a semiconductor material manufacturing facility and is then provided to a fabrication facility. At the latter facility, several layers are processed onto the semiconductor wafer surface. Once completed, the wafer is then cut into one or more chips and assembled into packages. Although the processed chip includes several layers fabricated thereon, the chip still remains relatively flat. 
     SUMMARY OF THE INVENTION 
     The present invention, accordingly, provides an apparatus, system, and method for utilizing semiconductor spheres in a new and improved optical switch. A system and method of utilizing spherical, hemispherical and other portions of a spherical shaped devices to function as an optical switch is disclosed. The optical switch can contain mirrors that turn on and off, or are fixed in place with a movable spherical device. Additionally, the optical switches can contain grating patterns to deflect an optical signal from its original path. The grating patterns can vary in design and pattern to deflect the optical signal in almost any direction, or to not let the optical signal continue. The optical switch can also include photo sensors along the exterior of the sphere or along the reflection device. The optical switch can also include an integrated circuits. 
     An object of the present invention is to provide optical switches that deflect, reflect and absorb optical signals utilizing a multitude of methods and systems. 
     Additionally, another object of the present invention is to provide intelligence to optical switches. 
     Further, another object of the present invention is to provide inexpensive methods and systems for optical switching in general. 
     Therefore, in accordance with the previous summary, objects, features and advantages of the present invention will become apparent to one skilled in the art from the subsequent description and the appended claims taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a conventional optical switch with the mirror activated; 
     FIG. 2 illustrates a conventional optical switch with the mirror off; 
     FIG. 3 is a diagram of a complex system of optical components; 
     FIG. 4 is a diagram of one embodiment when a mirror is turned off; 
     FIG. 5 is a diagram of one embodiment when a mirror is turned on; 
     FIG. 6 is a three dimensional diagram of an embodiment similar to FIG. 5; 
     FIG. 7 is a three dimensional diagram of an embodiment with multiple spheres; 
     FIG. 8 is a set of diagrams of another embodiment; 
     FIG. 9 is another diagram of the embodiment in FIG. 8; 
     FIG. 10 is a three dimensional diagram of an embodiment similar to FIG. 8; 
     FIG. 11 is a diagram of an embodiment with multiple spheres; 
     FIG. 12 is a three dimensional diagram of another embodiment; 
     FIG. 13 is a two dimensional diagram of the embodiment in FIG. 12; 
     FIG. 14A is another two dimensional diagram of the embodiment in FIG. 12; 
     FIG. 14B is another diagram of the additionally embodiment; 
     FIG. 15 is a three dimensional diagram of multiple spheres; 
     FIG. 16 is a diagram of another example embodiment; 
     FIG. 17 is a diagram of yet another example embodiment; 
     FIG. 18 is a diagram of yet another example embodiment; 
     FIG. 19 is a diagram of yet another example embodiment; 
     FIG. 20 is a diagram of yet another example embodiment; 
     FIG. 21 is a diagram of yet another example embodiment; 
     FIG. 22 is a diagram of yet another example embodiment; and 
     FIG. 23 is a cross sectional diagram of the example embodiment in FIG.  22 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention can be described with several examples given below. It is understood, however, that the examples below are not necessarily limitations to the present invention, but are used to describe typical embodiments of operation. 
     Now referring to FIG. 3, an optical cable  70  is shown as input into a grating wave decoupler  72 . The grating wave decoupler will be described in greater detail later in the text, but as can be seen, a grating  74  on one end of the sphere  72  diffracts the incoming light signal  70  into three different sets of signals  76 ,  78 , and  80  into the set of liquid crystal (LC) grating switches  82 ,  84 , and  86 . In this example, the original signal  70  is divided into ranges of optical wavelengths by the LC grating  74  that result in Intermediate signals  76 ,  78  and  80 . 
     Intermediate signal  76  is input into the first LC grating switch  82  while intermediate signals  78  and  80  are input into the second and third LC grating switches  84  and  86 . 
     In this example, the LC grating switches are utilized as time sharing switches that output into several signals according to time. For example, intermediate signal  76  is output through the LC grate  88  as three signals  90 ,  92  and  94 . Likewise, intermediate signal  78  is output through LC grate  96  as three signals  98 ,  100  and  102  and intermediate signal  80  is output through LC grate  104  as three signals  106 ,  108  and  110 . 
     However, the LC grating switches can also be designed to divide the output by wavelength as well as by time. Additionally, the LC grating switches can be designed to have the grating on both sides of the sphere or just on one side. Moreover, the LC grating can be designed to alternate grates to deflect an incoming signal in different directions as the grates alternate. 
     Further, in this example, signals  90 ,  92 ,  94 ,  98 ,  100 ,  102 ,  106 ,  108  and  110  are input into the sphere light exchanger  112 . The spheres inside the light exchanger  112  illustrate how a light signal can be switched from a path and made to turn ninety degrees into another path. 
     One example of how to make a sphere with a mirror to operate as a optical switch is to polish the sphere in half and then attach another half that has been polished by optical with optical glue. However, before the two halves are attached, a layer of LC (and photo sensors or integrated circuits if desired) is formed on one surface. The LC acts as a mirror when it is on, and is transparent when it is off. 
     FIG. 4 illustrates a sphere  398  with input signals  400  and  402  passing through the sphere when the LC mirror  404  is off. The input signals  400  and  402  enter into the sphere  398  through polished flat areas  406  and  408  respectively. The polished flat areas  406  and  408  ensure that no light gets diffracted because of the curvature of the sphere. Likewise, the signals  400  and  402  exit the sphere  398  through polished flat areas  410  and  412 . 
     FIG. 5 illustrates the same sphere  398  as FIG. 4, but, with the LC mirror  404  on. Since the mirror  404  is on, the first signal  400  enters the sphere through polished flat area  406 , is reflected at the mirror  404  and exits through polished flat area  410  ninety degrees, or perpendicular, to the angle that the signal  400  entered the sphere  398 . Likewise, signal  402  enters the sphere  398  through polished flat area  408 , reflects at mirror  404 , and exits at polished flat area  412  ninety degrees, or perpendicular from the angle that the signal entered the sphere  398 . Although, this example illustrates a ninety degree reflection, the invention is not limited to reflecting an optical signal at ninety degrees and other angles of reflection could easily be designed into the device. 
     A three dimensional view of the sphere  398  with the LC mirror  404  is shown in FIG.  6 . The signal  400  enters the sphere  398  through area  406  and exits through  412  when the mirror  404  is off. Likewise, when the mirror  404  is on, the signal  400  gets reflected and exits the sphere  398  through area  410 . 
     FIG. 7 illustrates an example of how a LC mirror exchanger can be embodied. Input signal  700  goes through spheres and gets reflected when it enters the third sphere because the third sphere has the mirror on. The signal then exits as output signal  714 . Likewise, input signal  702  goes through three spheres with the mirrors off, and then gets reflected into output signal  716  because the fourth sphere&#39;s mirror is on. Similarly, input signal  718  goes through one sphere and gets reflected into output signal  712  at the second sphere because it&#39;s mirror is on. Input signals  706  and  708  also get reflected into output signals  710  and  718  because the first sphere and the last sphere in each path, respectively, have its&#39; mirrors on. 
     FIG. 8 illustrates how the LC grating spheres can be implemented. Sphere  806  has two separate gratings  802  and  804 . Depending on the spacing and width of the grating, input signal  800  can be deflected into direction  808  or  810 . The grating can be made so that only grating  804  is needed to deflect the signal into either direction  808  or  810  by reversing the grating  804 . However, gratings  802  and  804  can be configured so that both are required to turn on so that the signal gets deflected. With either configuration, when the grating is off, input signal  800  goes through the sphere  806  into output signal  812 . 
     Similarly, the input signal  820  in sphere  822  goes straight through into output signal  830  when the gratings  824  and  826  are off, and gets deflected into directions  832  and  828  when at least one of the gratings  824 ,  826  are on. 
     Likewise, input signal  850  in sphere  852  goes straight through to output signal  862  when the gratings  854  and  856  are off, and gets deflected into directions  856  and  858  when at least one of the gratings  854 ,  856  are on. 
     These three examples are shown to illustrate how three different input signals can exit the sphere in three different directions in a combination of five possible output paths. FIG. 9 shows the combination of possible input and possible output paths. Input signal  900  can go straight through into output signal  902  or get deflected into output signals  904  or  906  when at least one grating  908  or  910  is on. Likewise, input signal  912  can go straight through into output signal  906  or get deflected into output signals  902  or  914  when at least one grating  908  or  910  is on. Similarly, input signal  916  can go straight through into output signal  914  or get deflected into output signals  906  or  918  when at least one grating  908  or  910  is on. 
     FIG. 10 illustrates a three dimensional example of the grating optical switch. The optical signal  1000  goes into sphere  1002  and goes straight through to output signal  1004  when the gratings  1006  and  1008  are off. When at least one grating  1006  or  1008  are on, the input signal  1000  gets deflected into output signals  1010  or  1012 . 
     FIG. 11 illustrates an implementation of a optical switch exchanger with LC grating switches. Input signal  1100  goes into the first optical grating switch and gets deflected because the grating(s) is on at the first optical switch. The signal  1100  then goes through four optical switches without getting deflected and then gets deflected at the last switch because the grating is on. The input signal  1100  then exits the exchanger as output signal  1102 . Similarly, input signal  1104  gets deflected at the first optical switch and goes through two optical switches and then gets deflected when the next optical switch&#39;s grating is on. The signal  1104  then exits the exchanger as output signal  1106 . The input signal  1108  goes through four optical switches without getting deflected and then gets deflected twice in a row when the next two switches have their gratings on, and exits the system as output signal  1110 . Input signal  1112  gets deflected at the first switch since the grating is on, and then goes through one switch and gets deflected at the next switch and exits the exchanger as output signal  1114 . Input signal  1116  gets deflected at the first and second switch because the grating is on both of them, and goes through two switches and gets deflected two more times at the next two switches since their gratings are on too. The signal  1116  then exits the exchanger as output signal  1118 . Input signal  1120  gets deflected at the first switch since the grating is on, and then goes through four optical switches and gets deflected at the next switch since the grating is on. The signal  1120  then exits the exchanger as output signal  1122 . 
     Although the example above was shown with only one input signal into each switch, as many as three input signals with the current embodiment can be input into each switch and then be either deflected or pass through depending on whether the grating is on or not. 
     Another embodiment of the optical switch is implemented with the use of a floating sphere within an outer shell as detailed in the incorporate by reference patent application entitled a “method of making small gaps for small electrical/mechanical devices” listed above. FIG. 12 illustrates such an implementation within the application of an optical switch. In this embodiment, the mirror  1200  is not an LC, but a more permanent mirror that gets into position by rotating the inner sphere  1202  within the outer shell  1204 . A cavity  1206  is shown in between the outer shell  1204  and the inner sphere  1202 . 
     The inner sphere  1202  is coated with a metal coating  1208  (or coil  1207 ) which allows the coils  1210  (or metal coating not shown) on the outer shell  1204  to levitate and rotate the inner sphere  1202  when required. The inner sphere  1202  and outer shell  1204  have a cavity  1206  that separates the two. When the coils  1210  on the outer shell  1204  are turned on, the inner sphere  1202  turns and moves the mirror  1200  to either let the optical signal pass through on the same plane, or reflect and turn the optical signal ninety degrees as shown in the previous figures. The following table illustrates a few examples of how the inner sphere  1202  can be levitated and rotated within the outer shell  1204 . 
     
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 inner ball 
                 shell 
                 force 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 levitation 
                 metal 
                 coil 
                 magnetic 
               
               
                   
                 levitation 
                 metal 
                 metal 
                 electro static 
               
               
                   
                 orientation 
                 coil 
                 coil 
                 magnetic 
               
               
                   
                   
               
             
          
         
       
     
     Four windows  1212  are polished off flat on the outer shell  1204  on the same plane and ninety degrees from each other. However, the windows are not required to be polished. When the mirror  1200  is on the same plane as the optical signal and thus the four windows  1212 , the optical signal is un-interrupted and the optical signal passes through the inner sphere  1208  and out the exit window  1214 . 
     An example of how the inner sphere  1208  reflects an optical signal follows. When an optical signal passes through window  1216 , it passes into the inner sphere through a corresponding window, reflects on the mirror, and passes out of the inner sphere through an opposite corresponding window on the inner sphere and out exit window  1214  on the outer sphere. 
     FIG. 13 shows a two dimensional example of the an optical signal going into the outer sphere through window  1402  into corresponding inner sphere window  1404  and out of inner sphere window  1406  as the mirror  1408  is on the same plane as the optical signal. The signal then exits the corresponding outer shell window  1410 . Inner ball window  1412  is also on the same plane as the mirror while its corresponding inner ball exit window is not shown, but is directly on the other side of the inner ball and on the same plane as the mirror. Inner ball windows  1414  and  1416  are used to reflect light, but not used in this figure. 
     FIG. 14A shows the outer shell  1400  moved in relation to the inner ball. In this example, the optical signal enters the same outer shell window  1402 , but enters inner ball window  1414  instead and then reflects off the mirror  1408  and out inner ball window  1416  and through outer shell window  1412 . Although the figures show that the outer shell moved in relation to the inner ball, the inner ball actually moves in order to move the mirror in place to switch the optical signal. 
     FIG. 14B is another example that would have an incoming optical signal  1480  deflect because of the index of refraction of the material into the mirror  1408  and reflect into the outgoing signal  1482 . Similarly, incoming signal  1484  would deflect and reflect on the mirror  1408  into outgoing signal  1486 . 
     FIG. 15 shows an example of spherical shaped devices that either include gratings or mirrors, but are configured as a three dimensional array of spherical devices  1500 . In this example, the three dimensional array of spherical devices  1500  has an input side  1502 , but can output signals in any direction  1504 ,  1506 , and  1508 . 
     FIG. 16 shows an example of one embodiment of the present invention. In this example, the spherical device is actually only a hemisphere  1600  and has a cavity in the center. However, a metal film  1604  is formed over the solid edges  1606  of the hemisphere. This example embodiment can replace the spherical device with a fixed mirror position. The preferred implementation of this example would include a mirror that turns on and off. This example also includes SiO2 as the material of the hemisphere. 
     FIG. 17 shows a cavity  1700  within a spherical device  1702  with a fixed mirror  1704 . 
     FIG. 18 shows another embodiment of a spherical device  1800  with a cavity  1802  in the center and a center portion  1804  that acts as a mirror. The mirror  1804  can be comprised of a metal film or an elastic material that joins the two hemispheres. In the case of an elastic material, preferably it would be composed of a material that changes it&#39;s index of refraction when it expands. 
     FIG. 19 shows an example of an embodiment with the inner sphere  1900  of SiO2 that has a cavity  1902  within the sphere  1900  and mirror  1904  composed of metal film. The inner sphere  1900  is within an outer sphere  1906  and has a cavity  1908  between both spheres. 
     FIG. 20 illustrates another embodiment of a sphere  2000  with sensors  2002  are placed on a mirror  2004  to gather information on an optical signal. The sensors  2002  shown are also connected to an integrated circuit  2006  on the substrate of the sphere  2000  such as disclosed in the incorporated by reference patent entitled “a method and system for manufacturing spherical-shaped semiconductor integrated circuits”. 
     The sensors  2002  could gather all types of information on optical signals such as phase, amplitude, wavelength and rate. Additionally, the sensors  2002  could be used to read the optical signal for various functions such as error checking. With the combination the sensors  2002  and the integrated circuit  2006 , the spherical optical switch  2000  becomes an intelligent optical switch that can be expanded to a multitude of functions. 
     FIG. 21 illustrates a sphere  2100  with sensors  2102  placed on the flat polished areas  2104  instead or in addition to sensors on a mirror. The sensors  2102  would also be connected to an integrated circuit  2106  in this embodiment. 
     FIG. 22 illustrates another embodiment. This sphere  2200  includes a polished flat area  2202  receiving an incoming optical signal, and a polished flat area  2204  where the corresponding outgoing optical signal exits the sphere  2200 . Additionally, this switch is designed with material that changes its index of refraction upon a standing wave created when portions  2206  and  2208  of piezo-electric (PZT) material are activated. 
     FIG. 23 illustrates a cut-out portion of the sphere  2200  as the portions of PZT  2206  and  2208  are activated. In this example, the standing wave compresses the material of the sphere causing it to changes its index of refraction in order to redirect the incoming signal. Although the example illustrates a ninety degree turn, almost any angle could be implemented depending on material used and how much pressure the standing wave creates on the material. 
     It is understood that several variations may be made in the foregoing. For example, the spheres can be made of other materials used in conventional semiconductor processing. Additionally, any spherical lens effect can be compensated by the design of grating. Some materials for the sphere/hemisphere are silicon for longer wavelengths, fused silicon for shorter wavelength, optical glass and acrylic glass. Although, the silicon spheres are usually ground to cut them in half, the optical glass and acrylic glass can be molded into a hemisphere or ground in half. 
     The mirror can be composed of a metal layer, liquid crystal, and/or an air gap that is turned on and off by pressure. Additionally, a piezo electric material can be placed on the periphery of a center cut portion with a gap in center that can be filled with gas or liquid from outside the sphere. Moreover, an elastic material could be placed on the periphery of a center cut portion with similar materials to fill the gap as the piezo electric embodiment. 
     Further, a material that changes index of refraction upon electric charge, magnetic field or ultrasonic sound could replace the mirror area of the sphere. 
     Other modifications, changes and substitutions are intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.