JP6034319B2 - Light switch - Google Patents

Description

  The present invention relates to an optical switch.

  Conventionally, in an optical transmission system, an optical switch has been used to switch an optical path of signal light. Such an optical switch generally includes a reflection mirror (hereinafter referred to as a MEMS mirror) or LCOS (Liquid Crystal On Silicon) using MEMS (Micro Electro Mechanical Systems) technology as an optical path switching unit that switches an optical path of signal light. . The MEMS mirror is supported so as to be rotatable around a predetermined rotation axis, and its rotation angle is adjusted by a drive mechanism. An optical switch provided with a MEMS mirror realizes an optical switch operation by reflecting signal light incident from a certain optical path by the MEMS mirror and outputting the reflected signal light to a specific optical path. On the other hand, LCOS is a spatial light modulator that modulates the phase of incident light with liquid crystal and diffracts it. An optical switch having an LCOS realizes an optical switch operation by diffracting signal light incident from a certain optical path by the LCOS and outputting it to a specific optical path.

  As a conventional technique of the optical switch as described above, for example, in Patent Document 1, WDM signal light in which signal lights having different wavelengths are wavelength-division multiplexed (Wavelength Division Multiplexing) is input, and this WDM signal light is input. A wavelength selective switch that switches the optical path of the included signal light for each wavelength is disclosed. In Patent Document 1, a wavelength selective optical switch in which optical fiber ports for inputting and outputting signal light are arranged one-dimensionally, and a wavelength selective light in which the number of optical fiber ports is increased by arranging optical fiber ports two-dimensionally. And a switch. On the other hand, Patent Document 2 discloses a so-called 2 in 1 wavelength selective optical switch in which two different wavelength selective optical switch functions are incorporated in one apparatus.

JP 2011-65023 A US Pat. No. 7,769,255

  By the way, the optical communication system has been developed from a point-to-point type to a ring type or mesh type network form as the optical transmission technology is improved. The node of the optical network having such a configuration requires an optical switch for inputting / outputting arbitrary signal light to / from an arbitrary port and arbitrarily changing the optical path of the signal light. In particular, when WDM signal light is used, a wavelength selective optical switch that can arbitrarily change the optical path for signal light of an arbitrary wavelength is required. In recent years, with the increase in the scale of optical networks, it is increasingly required to increase the number of optical input / output ports of optical switches including wavelength selective optical switches.

  However, in the above-described prior art, when the number of ports of the optical switch is increased, it is difficult to avoid an increase in the size of the optical components constituting the optical switch such as the optical path switching unit or the lens system. This will increase the size and cost of optical switches.

  Further, in the 2-in-1 wavelength selective optical switch described in Patent Document 2, it is necessary to condense signal light from a group of light input / output port arrays on an optical path switching unit for optical switch operation. The width of the system port array in the arrangement direction is increased. For this reason, it is difficult to avoid an increase in the size of the optical components constituting the optical switch, and this causes an increase in the size and cost of the optical switch.

  The present invention has been made in view of the above, and it is an object of the present invention to provide an optical switch capable of easily increasing the number of optical input / output ports while suppressing an increase in device size and cost. Objective.

In order to solve the above problems, the present invention provides a plurality of light input / output units each having a port group composed of a plurality of ports for inputting or outputting light, and an optical path of light input from an input port in the port group. An optical path operation unit having a plurality of optical path switching units that switch the optical input / output units to the optical path toward the output port in the same port group, and the light input from the plurality of optical input / output units side for each port group A condensing lens that condenses light on the plurality of optical path switching units and optically couples light input from the plurality of optical path switching units to the plurality of light input / output units for each port group; and the plurality of lights A plurality of light input / output units, each of which has a wavelength dispersion element that wavelength-disperses each light input from the input / output unit side in a direction substantially perpendicular to a switch axis direction that is an arrangement direction of the light input / output units. It said port, each having parts Optical path groups between the input light from which is characterized in that intersect so that at least partially overlaps Te wherein the condenser lens smell.
According to such a configuration, it is possible to provide an optical switch that can easily increase the number of optical input / output ports while suppressing an increase in device scale and cost.

Further, according to the present invention, when the aperture diameter of the wavelength dispersion element in the switch axis direction is H1, and the aperture diameter of the condenser lens in the switch axis direction is H2, the relationship of H1 ≧ H2 is established. It is characterized by.
According to such a configuration, the width of the optical switch in the switch axis direction can be reduced.

Further, the invention is characterized in that the wavelength dispersion element is disposed at a position separated by a focal length of the condenser lens.
According to such a configuration, it is possible to eliminate the difference in the incident angle of the signal light having different wavelengths dispersed by the wavelength dispersion element to the optical path switching unit.

The present invention further includes an optical element disposed on the light input / output unit side of the condenser lens and having a plurality of different refractive powers in the switch axis direction, and the optical element is input from the port group. Alternatively, the optical path group of the output light is refracted at different angles for each optical path group by the plurality of different refracting powers, and crosses so that at least a part of the condensing lens overlaps .
According to such a configuration, the plurality of light input / output units can be arranged in parallel by refracting the signal light by the optical element.

Further, the invention is characterized in that the optical element having a plurality of different refractive powers in the switch axis direction is a prism having a plurality of different refractive powers in the switch axis direction.
According to such a configuration, a plurality of light input / output units can be arranged in parallel by using a prism having an appropriate refractive power.

Further, the invention is characterized in that the optical element having a plurality of different refractive powers in the switch axis direction is disposed in the vicinity of the wavelength dispersion element.
According to such a configuration, the signal light from the plurality of light input / output units can be set to a desired position that does not overlap on the optical path switching unit and is not too far away.

Further, the present invention is characterized in that the last beam waist existing on the light input / output unit side from the condensing lens is present in the vicinity of the wavelength dispersion element or thereafter.
According to such a configuration, since the spot diameter of the signal light in the condenser lens can be reduced, the apparatus can be further miniaturized.

In the invention, it is preferable that the optical element having a plurality of different refractive powers in the switch axis direction has a light propagation length from the light input / output unit within about 50 mm.
According to such a configuration, it becomes possible to reduce the vignetting of the signal light in the portion where the refractive power of the optical element having a plurality of different refractive powers in the switch axis direction.

In the invention, it is preferable that the aperture diameter of the condensing lens in the switch axis direction is about 15 mm or less.
According to such a configuration, for example, the optical switch casing having a reference width of 19.4 mm can be accommodated with a margin.

The present invention is also characterized in that when the beam divergence angle of light input from the light input / output unit is θ, the angle formed by the optical path when any two port groups are selected is approximately 2θ. And
According to such a configuration, even when the spread of the beam is taken into consideration, the aperture diameter required for the condensing lens or an element in the vicinity thereof can be reduced, and the optical switch can be further miniaturized.

In the present invention, when the beam divergence angle of the light input from the light input / output unit is θ, the angle formed by the optical path when any two port groups are selected is approximately 2θ or more. Features.
According to such a configuration, even when the spread of the beam is taken into consideration, the aperture diameter required for the condensing lens or an element in the vicinity thereof can be reduced, and the optical switch can be further miniaturized.

In the present invention, an optical element having a plurality of different refractive powers in the switch axis direction is disposed in the vicinity of the optical path operation unit, and an incident angle of light incident on the optical path switching unit is adjusted for each port group. It is characterized by doing.
According to such a configuration, by adjusting the incident angle, loss of signal light can be reduced and crosstalk characteristics can be improved.

Further, the invention is characterized in that the optical element having a plurality of different refractive powers in the switch axis direction is a prism having a plurality of different refractive powers in the switch axis direction.
According to such a configuration, the loss of signal light can be reduced and the crosstalk characteristic can be improved by adjusting the characteristics of the prism.

Further, in the present invention, when a port to which light is input from the outside to the port group is a Com port, the light of the Com port specularly reflected by the optical path switching unit is located at both ends of the port group. The angle formed by the incident light from the port is approximately bisected.
According to such a configuration, the loss of signal light can be reduced and the crosstalk characteristic can be improved by minimizing the diffraction angle at the time of switching.

Further, the present invention is characterized in that the optical path switching unit is configured by LCOS (Liquid Crystal on Silicon).
According to such a configuration, even when LCOS is used, loss of signal light can be reduced and crosstalk characteristics can be improved by minimizing the diffraction angle at the time of switching.

  According to the present invention, it is possible to provide an optical switch capable of easily increasing the number of optical input / output ports while suppressing an increase in device scale and cost increase.

It is a figure which shows the structural example of the optical switch which concerns on 1st Embodiment of this invention. It is the figure which looked at the optical switch shown in FIG. 1 from the X-axis direction. It is a figure which shows the structural example of the optical path operation part shown in FIG. It is a figure for demonstrating operation | movement of the prism shown in FIG. It is a figure which shows the relationship between the divergence angle of the beam shown in FIG. 1, and the angle which beams make. It is a figure which shows the structural example of the optical switch which concerns on 2nd Embodiment of this invention. It is the figure which looked at the optical switch shown in FIG. 6 from the X-axis direction. It is a figure which shows the structural example of the optical switch which concerns on 3rd Embodiment of this invention. It is the figure which looked at the optical switch shown in FIG. 8 from the X-axis direction. It is a figure for demonstrating operation | movement of the prism shown in FIG. It is a figure which shows the other structural example of the optical path operation part shown in FIG. It is a figure which shows the structural example of the optical switch which concerns on 4th Embodiment of this invention. It is the figure which looked at the optical switch shown in FIG. 12 from the X-axis direction. It is a figure which shows the structural example of the optical switch which concerns on 5th Embodiment of this invention. It is the figure which looked at the optical switch shown in FIG. 14 from the X-axis direction. It is a figure which shows the structural example of the optical switch which concerns on 5th Embodiment of this invention. It is the figure which looked at the optical switch shown in FIG. 16 from the X-axis direction.

  Next, an embodiment of an optical switch according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this Embodiment. Also, the drawings are schematic, and it should be noted that the relationship between the dimensions of each element, the ratio of each element, and the like may differ from the actual ones. Even between the drawings, there are cases in which portions having different dimensional relationships and ratios are included. In the drawing, directions will be described using an XYZ coordinate system, which is an orthogonal coordinate system of three axes (X axis, Y axis, Z axis) as appropriate.

(A) Description of First Embodiment First, the configuration of the optical switch according to the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing a configuration example of an optical switch according to the first embodiment of the present invention. FIG. 1 shows the optical switch according to the first embodiment viewed from the positive direction of the Z-axis direction of the XYZ coordinate system. FIG. 2 is a view of the optical switch shown in FIG. 1 as viewed from the positive direction of the X-axis direction of the XYZ coordinate system. As shown in FIGS. 1 and 2, the optical switch 10 includes a plurality of light input / output units 1 and 2, a prism 4, an optical path operation unit 5, a condenser lens 6, and an anamorphic optical system 7. A wavelength dispersion element 8, a polarization manipulation optical system 9, and a prism 11. Since each actual optical path in the optical switch 10 is greatly bent in the wavelength dispersion element 8, each component from the polarization manipulation optical system 9 to the optical path manipulation unit 5 (in the first embodiment, the polarization manipulation optical system 9). The prism 11, the anamorphic optical system 7, the condenser lens 6, the prism 4, and the optical path operation unit 5) are arranged with an angle before and after the wavelength dispersion element 8. However, in FIG. 1 and FIG. 2, each component is shown linearly along the optical path for simplification. This also applies to FIGS. 1 and 2 and subsequent drawings.

  The plurality of light input / output units 1 and 2 each have a port group for inputting or outputting light, and for each port group, input light from the outside or output light to the outside. Specifically, the optical input / output unit 1 includes an optical fiber port group 110, a collimator lens group 116 including a plurality of collimator lenses, and a support unit 117 that supports the optical fiber port group 110 and the collimator lens group 116. Prepare. The optical fiber port group 110 is an optical input / output port group including a plurality of optical fiber ports 111 to 115. Each of the optical fiber ports 111 to 115 is configured using an optical fiber that functions as an optical waveguide. The optical fiber ports 111, 112, 113, 114, and 115 are arranged at predetermined intervals (for example, equal intervals) along a predetermined arrangement direction, that is, a direction parallel to the YZ plane shown in FIG.

  The collimator lens group 116 includes collimator lenses arranged corresponding to the optical fiber ports 111 to 115. The collimator lens group 116 has a function of collimating the light output from the optical fiber ports 111 to 115 or condensing and coupling the input parallel light to the optical fiber ports 111 to 115.

  The optical input / output unit 2 includes an optical fiber port group 120, a collimator lens group 126 including a plurality of collimator lenses, and a support unit 127 that supports the optical fiber port group 120 and the collimator lens group 126. The optical fiber port group 120 is an optical input / output port group including a plurality of optical fiber ports 121 to 125. Each of the optical fiber ports 121 to 125 is configured using an optical fiber that functions as an optical waveguide. The optical fiber ports 121, 122, 123, 124, 125 are arranged at predetermined intervals such as equal intervals along a predetermined arrangement direction (a direction parallel to the YZ plane shown in FIG. 2).

  The collimator lens group 126 includes collimator lenses arranged corresponding to the optical fiber ports 121 to 125. The collimator lens group 126 has a function of making the light output from the optical fiber ports 121 to 125 parallel light, or condensing and coupling the input parallel light to the optical fiber ports 121 to 125.

  Hereinafter, the arrangement direction of the collimator lens groups 116 and 126 (direction parallel to the Z axis) will be referred to as the switch axis direction, and the wavelength dispersion direction (direction parallel to the X axis) of the wavelength dispersion element 8 described later will be described below. Then, it demonstrates as a wavelength dispersion axis.

  Here, as shown in FIGS. 1 and 2, the optical input / output units 1 and 2 are arranged along the arrangement direction of the optical fiber port groups 110 and 120, that is, the Z-axis direction. In the optical input / output units 1 and 2, the optical fiber port group 110 and the optical fiber port group 120 are grouped by the optical input / output units 1 and 2 and arranged in the same plane parallel to the YZ plane. The optical fiber ports 111 to 115 and 121 to 125 in the optical fiber port groups 110 and 120 are the same port group as viewed from the direction perpendicular to the arrangement direction (that is, the X-axis direction shown in FIGS. 1 and 2). And are parallel to each other between different port groups.

  The optical fiber ports 111 to 115 and 121 to 125 described above are for inputting light from the outside or outputting light to the outside separately for the light input / output units 1 and 2. Thus, each light inputted / outputted by the light input / output units 1 and 2 is not particularly limited, but is signal light for optical communication having a wavelength of 1520 to 1620 nm, for example.

  The optical path operating unit 5 includes a plurality of optical path switching units 5a and 5b that switch the optical path of the input light, and operates the optical path of light from the input port to the output port for each of the light input / output units 1 and 2. As shown in FIG. 2, the optical path switching units 5 a and 5 b are separately arranged in the Z-axis direction by different light input / output units 1 and 2. FIG. 3 is a schematic diagram illustrating a configuration example of a plurality of optical path switching units in the first embodiment. As shown in FIG. 3, the optical path switching unit 5a includes a plurality of LCOSs 5a-1, 5a-2, 5a-3, and 5a-4 arranged along the X-axis direction. Similarly, the optical path switching unit 5b includes a plurality of LCOSs 5b-1, 5b-2, 5b-3, 5b-4 arranged along the X-axis direction. The optical path switching units 5a and 5b having such a configuration are configured so that the optical path of light input from an input port in any one of the optical fiber port groups 110 and 120 is the same light to which the input port belongs. The optical input / output units 1 and 2 are switched to the optical path toward the output port in the fiber port group.

  That is, each LCOS 5 a-1, 5 a-2, 5 a-3, and 5 a-4 diffracts the light input from the input port in the optical fiber port group 110 of the optical input / output unit 1 and in the same optical fiber port group 110. It has the function to output toward the output port. Each LCOS 5b-1, 5b-2, 5b-3, 5b-4 diffracts light input from an input port in the optical fiber port group 120 of the optical input / output unit 2 to diffract light in the same optical fiber port group 120. It has the function to output toward the output port. The input port in the optical fiber port group 110 is one of the optical fiber ports 111 to 115, and the output port in the optical fiber port group 110 is the input port of the optical fiber ports 111 to 115. Any one except. The input port in the optical fiber port group 120 is any one of the optical fiber ports 121 to 125, and the output port in the optical fiber port group 120 is the input port of the optical fiber ports 121 to 125. Any one except.

  Here, each light input from the light input / output units 1 and 2 to the optical path operation unit 5 is separated in the Z-axis direction so as not to interfere with each other in the optical path switching units 5a and 5b. For example, as shown in FIG. 3, the imaging point P1 of light input from the light input / output unit 1 side to the LCOS 5a-1 of the optical path switching unit 5a is the LCOS 5b-1 of the optical path switching unit 5b from the light input / output unit 2 side. Is sufficiently separated from the image forming point P2 of the light input to. That is, the separation distance between the imaging point P1 and the imaging point P2 (hereinafter referred to as the separation distance d) is sufficiently larger than the dimension in the Z-axis direction of the beam spot of each light (see the hatched portion in FIG. 3). Big. As a result, interference between these lights is avoided. The same applies to the remaining LCOSs 5a-2 to 5a-4 and 5b-2 to 5b-4. The LCOSs 5 a-1 to 5 a-4 and 5 b-1 to 5 b-4 are arranged on the optical path operation unit 5 corresponding to the image forming points of the respective lights from the light input / output units 1 and 2 side. .

  The beam shape of each light input to each of the above-described LCOSs 5a-1 to 5a-4 and 5b-1 to 5b-4 is shown in the hatched portion of FIG. 3 by the action of the anamorphic optical system 7 described later. As illustrated, it is shaped into an elliptical shape reduced in the X-axis direction. The widths W2 of the LCOSs 5a-1 to 5a-4 and 5b-1 to 5b-4 are sufficiently larger than the width W1 of each elliptical light.

  The condensing lens 6 condenses the light input from the plurality of light input / output units 1 and 2 on the plurality of optical path switching units 5a and 5b separately for the optical fiber port groups 110 and 120, and the plurality of optical path switching units 5a and 5b. The light input from the 5b side is optically coupled to a plurality of optical input / output units 1 and 2 for each of the optical fiber port groups 110 and 120. As a result, the plurality of light input / output units 1 and 2 and the optical path operation unit 5 are optically coupled by the condenser lens 6. Specifically, the condenser lens 6 is a lens having a single optical axis 6 a and is disposed between the light input / output units 1 and 2 and the optical path operation unit 5. The condensing lens 6 condenses the light from the optical fiber port group 110 on one optical path switching unit 5a and condenses the light from the optical fiber port group 120 on the other optical path switching unit 5b. The condensing lens 6 optically couples light from the optical path switching unit 5a to one optical fiber port group 110 and optically couples light from the optical path switching unit 5b to the other optical fiber port group 120. To do. In any case, the condenser lens 6 collects light in a plane parallel to the Z-axis direction (for example, in a plane parallel to the YZ plane) as shown in FIG. 2, and as shown in FIG. The light is condensed in a plane parallel to the X-axis direction (for example, in a plane parallel to the XY plane). Here, the Z-axis direction is an arrangement direction of the optical fiber port groups 110 and 120, and the X-axis direction is a direction perpendicular to the arrangement direction. In addition, it is desirable that the position of the focal point of such a condenser lens 6 substantially coincides with the position of the optical path operation unit 5 described above. As shown in FIGS. 1 and 2, when the focal length of the condenser lens 6 is f, the optical path operation unit 5 is disposed at a position approximately f away from the condenser lens 6 in the Y-axis direction, and wavelength dispersion The element 8 is preferably arranged at a position separated from the condenser lens 6 in the Y-axis direction by about f. Further, the aperture diameter of the condenser lens 6 and the width in the Z-axis direction are set to about 15 mm or less. By setting the aperture diameter of the condenser lens 6 and the width in the Z-axis direction to be approximately 15 mm or less, the optical switch 10 having a reference width of 19.4 mm can be accommodated with a margin. .

  The polarization manipulation optical system 9 is an optical system that manipulates and outputs the polarization state of input light so that it is composed of only a single polarization direction. For example, a Wollaston prism and a half-wave plate Consists of. If the polarization state modulated by LCOS is linearly polarized light parallel to the x axis, the Wollaston prism separates input light into linearly polarized light parallel to the x axis and linearly polarized light parallel to the y axis, and the y axis By applying a half-wave plate whose fast axis is inclined by 45 ° with respect to the y-axis only for linearly polarized light parallel to, the polarization state is a straight line parallel to the x-axis. It becomes only polarized light and can be diffracted by LCOS.

  The prism 11 refracts the parallel optical path groups output from the collimator lens groups 116 and 126 arranged in the switch axis direction so as to cross each other. As a result, the optical path groups output from the collimator lens groups 116 and 126 intersect so as to overlap in the condensing lens 6 or in the vicinity thereof. In the example of FIG. 2, the optical path of the collimator lens 116 of the optical fiber port 111 intersects with the optical path of the collimator lens 126 of the optical fiber port 121 so as to overlap on the condenser lens 6. The optical paths of the collimator lenses 116 of the optical fiber ports 112 to 115 intersect with the optical paths of the collimator lenses 126 of the optical fiber ports 122 to 125 so as to overlap each other on the condenser lens 6. Here, as shown in FIG. 2, the aperture diameter of the condenser lens 6 including the beam spot in the switch axis direction is H2, and the aperture diameter of the wavelength dispersion element 8 including the beam spot in the switch axis direction is H1. In this case, a relationship of H1 ≧ H2 is established between them. Note that the propagation length of light from the collimator lens group 116 and the collimator lens group 126 to the prism 11 is preferably set to be 50 mm or less, for example. When the propagation length exceeds this, the light passing through the ports (optical fiber ports 111 and 115 and optical fiber ports 121 and 125 in FIG. 2) located at both ends of the prism 11 in the switch axis direction passes through the opening of the prism 11. This is because it may come off. Moreover, it is desirable to set the aperture diameter H2 of the condenser lens 6 in the switch axis direction to be 15 mm or less. This is because if the opening diameter exceeds this range, the switch axis direction cannot be sufficiently thinned.

  Here, the aperture diameter required for the element is calculated from the beam arrangement on the element and the beam shape. Usually, in the propagation of a Gaussian beam, an aperture diameter of about twice the spot size of the beam is required. In this example, considering the characteristics of the wavelength selective switch and thinning, when an appropriate positive coefficient is b, b times the spot size is the aperture diameter of the beam alone. Therefore, the aperture diameter of the element is the distance between the outermost edge and the optical axis among the areas swept by all the beams passing over the element, and at this time, the area swept by each beam is: This is a circle or ellipse region consisting of b times the beam spot size on the element. In the present embodiment, the value of b is assumed to be about 1.2 to 2 times.

  In FIG. 2, the optical path of the collimator lens group 116 of the optical fiber ports 111 to 115 overlaps the optical path of the collimator lens group 126 of the optical fiber ports 121 to 125 on the condenser lens 6. Although crossing each other, they do not have to be completely coincident with each other, and may be separated to some extent in the Z-axis direction.

  The anamorphic optical system 7 shapes the beam shape of each light input from the plurality of light input / output units 1 and 2 into an elliptical shape. Specifically, the anamorphic optical system 7 includes a cylindrical lens 7 a having a refractive power in the wavelength dispersion axis direction and an anamorphic prism 7 b, and includes the light input / output units 1 and 2 and the condenser lens 6. Arranged between. The anamorphic optical system 7 is configured so that the beam shape of each light input from the light input / output units 1 and 2 is perpendicular to the arrangement direction of the optical fiber ports 111 to 115 and 121 to 125 (that is, the X-axis direction). It has a function to expand. By such an action of the anamorphic optical system 7, the beam shape of each light from the light input / output units 1 and 2 is shown in a broken line portion of FIG. 3 when condensed to the optical path switching units 5a and 5b. As shown in the figure, it is shaped into an elliptical shape with a width W1 reduced in the X-axis direction. On the other hand, the anamorphic optical system 7 has a function of reducing the beam shape of light input from the optical path operating unit 5 side with respect to the X-axis direction.

  The wavelength dispersion element 8 wavelength-disperses each light input from the plurality of light input / output units 1 and 2 side. Specifically, the wavelength dispersive element 8 is configured using, for example, a transmission type diffraction grating or the like, and both the light from the light input / output unit 1 side and the light from the light input / output unit 2 side have a predetermined wavelength. Wavelength dispersion is performed in the dispersion direction (direction of the wavelength dispersion axis). Here, the chromatic dispersion direction of the chromatic dispersion element 8 is the direction of the plane in which the optical paths of the respective lights wavelength-dispersed by the chromatic dispersion element 8 form an angle. That is, in FIG. 1, this wavelength dispersion direction is substantially parallel to the X-axis direction and is substantially perpendicular to the arrangement direction of the optical fiber ports 111 to 115 and 121 to 125 shown in FIG. In such a wavelength dispersion element 8, the incident light between the anamorphic optical system 7 and the condenser lens 6 is wavelength-dispersed in the arrangement direction of the LCOSs 5a-1 to 5a-4 and 5b-1 to 5b-4. Is arranged to wake up. In this case, it is desirable that the position of the wavelength dispersion element 8 substantially coincides with the position of the focal point of the condenser lens 6. Further, it is desirable that the wavelength dispersive element 8 intersects the optical axis 6a of the condenser lens 6 at the central portion thereof. For example, when the wavelength dispersive element 8 is a diffraction grating, the groove direction of the condenser lens 6 is It is good to make it substantially perpendicular to the optical axis 6a.

  In the optical switch 10 having the configuration as described above, for example, an optical fiber port 113 arranged in the center in one optical fiber port group 110 and an optical fiber port 123 arranged in the center in the other optical fiber port group 120. Are set as a common optical fiber port (Com port) through which light is input from the outside. Further, the remaining four optical fiber ports 111, 112, 114, 115 in one optical fiber port group 110 and the remaining four optical fiber ports 121, 122, 124, 125 in the other optical fiber port group 120 are displayed. Are set as optical fiber ports for outputting light to the outside.

  Here, in the optical switch 10, when signal light having a predetermined wavelength is input from the optical fiber port 113 in one optical input / output unit 1, the optical fiber ports 111, 112, 114 in the same optical input / output unit 1 are used. , 115 can output the signal light from the optical fiber port assigned the wavelength. Further, the optical switch 10 is configured such that when signal light having a predetermined wavelength is input from the optical fiber port 123 in the other optical input / output unit 2, the optical fiber ports 121, 122, 124, It is possible to operate so as to output the signal light from the optical fiber port to which the wavelength is assigned. In other words, the optical switch 10 functions as a 2-in-1 optical switch having two 1 × 4 optical switch functions different in each optical input / output unit.

  In particular, when the signal light input from the fiber port 113 is a 4-channel WDM signal light including four signal lights having different wavelengths, the optical switch 10 includes the optical fiber ports 111, 112, 114, and 115. It is possible to operate so as to output the signal light of each channel included in the WDM signal light from the optical fiber port to which the channel is assigned. In addition, when the signal light input from the fiber port 123 is 4-channel WDM signal light including four signal lights having different wavelengths, the optical switch 10 includes each of the optical fiber ports 121, 122, 124, and 125. The optical fiber port to which the channel is assigned can operate so as to output the signal light of each channel included in the WDM signal light. In this case, the optical switch 10 functions as a 2 in 1 wavelength selective optical switch having two 1 × 4 wavelength selective optical switch functions different in each optical input / output unit.

  The prism 4 has two refracting powers that are different in the switch axis direction, and condenses the light input from the condensing lens 6 side on a plurality of optical path switching units 5a and 5b for each of the optical fiber port groups 110 and 120. The light input from the optical path switching units 5 a and 5 b is output to the condenser lens 6. Specifically, as shown in FIG. 4, the prism 4 refracts the angle θ1 formed by the signal light L2 and the signal light L5 located at both ends in the switch axis direction so that the signal light L1 is approximately divided into two. . Further, the prism 4 refracts the angle θ11 formed by the signal light L12 and the signal light L15 located at both ends in the switch axis direction so that the signal light L11 is approximately divided into two.

  Next, the operation of the optical switch 10 will be described with reference to FIGS. In the following, the optical switch operation on the one optical input / output unit 1 side of the two optical input / output units 1 and 2 included in the optical switch 10 will be described, and then the light on the other optical input / output unit 2 side will be described. Although the switch operation will be described, these two optical switch operations are performed independently of each other. That is, these two optical switch operations are performed in random order between the optical input / output unit 1 and the optical input / output unit 2.

  First, when the signal light L1 having the wavelength λ1 is input from the outside to the optical fiber port 113, the collimator lens group 116 converts the input signal light L1 into a substantially parallel light having a substantially circular beam shape. Next, the polarization manipulating optical system 9 manipulates and outputs the polarization state of the input light so that it consists only of a single polarization direction. The prism 11 refracts the signal light L1 output from the polarization operation optical system 9 in the direction of the optical axis 6a of the condensing lens 6 and outputs it. The anamorphic optical system 7 expands the beam shape of the signal light L1, which is substantially parallel light, in the X-axis direction and shapes it into an ellipse. Next, the wavelength dispersion element 8 diffracts the shaped signal light L1 at a diffraction angle corresponding to the wavelength λ1. Thereafter, the condensing lens 6 condenses the diffracted signal light L <b> 1 toward the optical path switching unit 5 a of the optical path operation unit 5. The prism 4 changes the incident angle of the light condensed toward the optical path switching unit 5a. The LCOS 5a-1 as one component of the optical path switching unit 5a diffracts the collected signal light L1 at a diffraction angle set corresponding to the output destination port of the wavelength λ1, and thereby the signal light L1 Is output as signal light L2 of wavelength λ1. The prism 4 and the condenser lens 6 pass the signal light L2 output from the optical path switching unit 5a in this way toward the optical input / output unit 1, and make the optical path parallel to the optical path of the signal light L1. In FIG. 1, the optical paths of the signal light L1 and the signal light L2 before and after the optical path switching are substantially overlapped.

  Next, the wavelength dispersion element 8 diffracts the signal light L2 input from the condenser lens 6 again. Next, the anamorphic optical system 7 reduces the beam shape of the signal light L2 in the X-axis direction to return to a substantially circular shape, and allows the signal light L2 to pass through the refractive optical system 9 to the light input / output unit 1 side. Such a refractive optical system 9, anamorphic optical system 7, and wavelength dispersion element 8 maintain a parallel relationship between the optical path of the signal light L1 and the optical path of the signal light L2, as shown in FIG. Yes. Thereafter, the signal light L2 is input to the collimator lens corresponding to the optical fiber port 111 assigned to the wavelength λ1 in the collimator lens group 116. The corresponding collimator lens collects the signal light L 2 and couples it to the optical fiber port 111. The optical fiber port 111 outputs the light thus combined, that is, the signal light L2 having the wavelength λ1 to the outside.

  As described above, the optical switch 10 changes the optical path of the signal light input from the optical fiber port 113 that is the Com port on the optical input / output unit 1 side to the optical fiber port 111 (same optical signal) assigned to the wavelength λ1. The optical path to the output port on the input / output unit 1 side can be switched.

  Further, if the wavelength of the signal light L1 input from the outside to the optical fiber port 113 is λ2, λ3, or λ4, the signal light L1 is transmitted to the refractive optical system 9 and the anamorphic light similarly to the case of the wavelength λ1 described above. After passing through the Fick optical system 7 and the like, the light is diffracted by the wavelength dispersion element 8 at a diffraction angle corresponding to the wavelength (λ2, λ3, or λ4). The wavelengths λ1, λ2, λ3, and λ4 are different from each other. The diffracted signal light L 1 reaches the condenser lens 6. The condensing lens 6 and the prism 4 condense the signal light L1 toward the LCOS portion corresponding to the wavelength of the signal light L1 in the optical path switching unit 5a. That is, the condensing lens 6 and the prism 4 condense the signal light L1 of wavelength λ2 onto the LCOS 5a-2, condense the signal light L1 of wavelength λ3 onto the LCOS 5a-3, or signal light of wavelength λ4. L1 is condensed on LCOS 5a-4. The LCOS 5a-2 diffracts the signal light L1 at a diffraction angle set corresponding to the output destination port of the wavelength λ2, and switches the optical path of the signal light L1 to the optical path of the signal light L3 of the wavelength λ2. Alternatively, the LCOS 5a-3 diffracts the signal light L1 at a diffraction angle set corresponding to the output destination port of the wavelength λ3, and switches the optical path of the signal light L1 to the optical path of the signal light L4 of the wavelength λ3. Alternatively, the LCOS 5a-4 diffracts the signal light L1 at a diffraction angle set corresponding to the output destination port of the wavelength λ4, and switches the optical path of the signal light L1 to the optical path of the signal light L5 of the wavelength λ4.

  The signal light after switching the optical path (that is, one of the signal lights L3 to L5) is the prism 4, the condensing lens 6, the wavelength dispersion element 8, the anamorphic optical system 7, as in the case of the wavelength λ1 described above. The refractive optical system 9 and the collimator lens group 116 are sequentially passed. The signal light after passing through the collimator lens is output to the outside from the optical fiber port corresponding to the wavelength in the optical fiber port group 110. That is, the signal light L3 having the wavelength λ2 is output to the outside from the optical fiber port 112 assigned to the wavelength λ2, and the signal light L4 having the wavelength λ3 is output to the outside from the optical fiber port 114 assigned to the wavelength λ3. The signal light L5 having the wavelength λ4 is output to the outside from the optical fiber port 115 assigned to the wavelength λ4.

  In particular, when the signal light L1 input from the outside to the optical fiber port 113 is a 4-channel WDM signal light including signal lights with wavelengths λ1, λ2, λ3, and λ4, the optical path of the WDM signal light has the above-described wavelength. As in the case of each signal light of λ1 to λ4, the optical path of the signal light L2 of wavelength λ1, the optical path of the signal light L3 of wavelength λ2, the optical path of the signal light L4 of wavelength λ3, and the signal light L5 of wavelength λ4 Switch to the optical path. Thereafter, the signal lights L2 to L5 derived from the WDM signal light are output to the outside from each of the optical fiber ports 111, 112, 114, and 115 assigned to the wavelengths λ1, λ2, λ3, and λ4. In this manner, the optical switch 10 can realize the switching of a desired optical path selected for each wavelength for the optical input / output unit 1.

  On the other hand, the optical input / output unit 2 performs an optical switch operation substantially similar to that of the optical input / output unit 1 described above. That is, when the signal light L11 having the wavelength λ11 is input from the outside to the optical fiber port 123 of the light input / output unit 2, the collimator lens group 126 converts the input signal light L11 into a substantially parallel beam having a substantially circular shape. Make it light. Next, the polarization manipulating optical system 9 manipulates and outputs the polarization state of the input light so that it consists only of a single polarization direction. The prism 11 refracts the signal light L11 output from the polarization operation optical system 9 in the direction of the optical axis 6a of the condenser lens 6 and outputs it. The anamorphic optical system 7 expands the beam shape of the signal light L11, which is substantially parallel light, in the X-axis direction and shapes it into an ellipse. Next, the wavelength dispersion element 8 diffracts the shaped signal light L11 at a diffraction angle corresponding to the wavelength λ11. Thereafter, the condensing lens 6 condenses the diffracted signal light L11 toward the optical path switching unit 5b (specifically, LCOS 5b-1 shown in FIG. 3) of the optical path operating unit 5. The prism 4 changes the incident angle of the light condensed toward the optical path switching unit 5b. The LCOS 5b-1 which is one component of the optical path switching unit 5b diffracts the collected signal light L11 at a diffraction angle set corresponding to the output destination port of the wavelength λ11, and thereby the signal light L11. Is output as the signal light L12 having the wavelength λ11. The prism 4 and the condenser lens 6 pass the signal light L12 output from the optical path switching unit 5b in this way toward the light input / output unit 2, and make the optical path parallel to the optical path of the signal light L11. In FIG. 1, the optical paths of the signal light L11 and the signal light L12 before and after the optical path switching are substantially overlapped.

  Next, the wavelength dispersion element 8 diffracts the signal light L12 input from the condenser lens 6 again. Next, the anamorphic optical system 7 reduces the beam shape of the signal light L12 in the X-axis direction to return to a substantially circular shape, and transmits the signal light L12 to the light input / output unit 2 side through the refractive optical system 9. Such a wavelength dispersion element 8, the anamorphic optical system 7, and the refractive optical system 9 maintain the parallel relationship between the optical path of the signal light L11 and the optical path of the signal light L12, for example, as shown in FIG. Yes. Thereafter, the signal light L12 is input to the collimator lens corresponding to the optical fiber port 121 assigned to the wavelength λ11 in the collimator lens group 126. The corresponding collimator lens collects the signal light L12 and couples it to the optical fiber port 121. The optical fiber port 121 outputs the light thus combined, that is, the signal light L12 having the wavelength λ11 to the outside.

  As described above, the optical switch 10 changes the optical path of the signal light input from the optical fiber port 123 that is the Com port on the optical input / output unit 2 side to the optical fiber port 121 (same optical signal) assigned to the wavelength λ11. The optical path to the output port on the input / output unit 2 side can be switched.

  If the wavelength of the signal light L11 input from the outside to the optical fiber port 123 is λ12, λ13, or λ14, the signal light L11 is transmitted to the refractive optical system 9 and the anamorphic light similarly to the case of the wavelength λ11 described above. After passing through the Fick optical system 7 and the like, the light is diffracted by the wavelength dispersion element 8 at a diffraction angle corresponding to the wavelength (λ12, λ13, or λ14). The wavelengths λ11, λ12, λ13, and λ14 are different from each other. The diffracted signal light L11 reaches the condenser lens 6. The condensing lens 6 and the prism 4 condense the signal light L11 toward the LCOS portion corresponding to the wavelength of the signal light L11 in the optical path switching unit 5b. That is, the condenser lens 6 and the prism 4 condense the signal light L11 having the wavelength λ12 onto the LCOS 5b-2, condensing the signal light L11 having the wavelength λ13 onto the LCOS 5b-3, or the signal light L11 having the wavelength λ14. Focus on LCOS5b-4. The LCOS 5b-2 diffracts the signal light L11 at a diffraction angle set corresponding to the output destination port of the wavelength λ12, and switches the optical path of the signal light L11 to the optical path of the signal light L13 of the wavelength λ12. Alternatively, the LCOS 5b-3 diffracts the signal light L11 at a diffraction angle set corresponding to the output destination port of the wavelength λ13, and switches the optical path of the signal light L11 to the optical path of the signal light L14 of the wavelength λ13. Alternatively, the LCOS 5b-4 diffracts the signal light L11 at a diffraction angle set corresponding to the output destination port of the wavelength λ14, and switches the optical path of the signal light L11 to the optical path of the signal light L15 of the wavelength λ14.

  The signal light after switching the optical path (that is, any one of the signal lights L13 to L15) is the same as in the case of the wavelength λ11 described above, the condenser lens 6, the wavelength dispersion element 8, the anamorphic optical system 7, and the refractive optical system. 9 and the collimator lens group 126 sequentially. The signal light after passing through the collimator lens is output to the outside from the optical fiber port corresponding to the wavelength in the optical fiber port group 120. That is, the signal light L13 having the wavelength λ12 is output to the outside from the optical fiber port 122 assigned to the wavelength λ12, and the signal light L14 having the wavelength λ13 is output to the outside from the optical fiber port 124 assigned to the wavelength λ13. The signal light L15 having the wavelength λ14 is output to the outside from the optical fiber port 125 assigned to the wavelength λ14.

  In particular, when the signal light L11 input from the outside to the optical fiber port 123 is a 4-channel WDM signal light including signal lights having wavelengths λ11, λ12, λ13, and λ14, the optical path of the WDM signal light has the above-described wavelength. Similarly to the case of each signal light of λ11 to λ14, the optical path of the signal light L12 of wavelength λ11, the optical path of the signal light L13 of wavelength λ12, the optical path of the signal light L14 of wavelength λ13, and the signal light L15 of wavelength λ14 Switch to the optical path. Thereafter, the signal lights L12 to L15 derived from the WDM signal light are output to the outside from each of the optical fiber ports 121, 122, 124, 125 assigned to the wavelengths λ11, λ12, λ13, λ14. In this manner, the optical switch 10 can realize the switching of a desired optical path selected for each wavelength for the light input / output unit 2.

  Each of the LCOSs 5a-1 to 5a-4, 5b-1 to 5b-4 (see FIG. 3) constituting the optical path switching units 5a and 5b described above has the following known configuration. That is, each of the LCOSs 5a-1 to 5a-4, 5b-1 to 5b-4 includes, for example, a pixel electrode group that is a reflective layer having a reflectance of approximately 100% on a silicon substrate on which a liquid crystal driving circuit is formed. The liquid crystal layer, which is a spatial light modulation layer, an alignment film, an ITO (Indium Tin Oxide) electrode, and a cover glass are sequentially laminated. This pixel electrode group is configured by arranging a large number of pixel electrodes in the Z-axis direction, which is the arrangement direction of the optical fiber port groups 110 and 120. Accordingly, the collimator lens group 116, the beam shape of the signal light incident on each of the LCOS 5 a-1 to 5 a-4, 5 b-1 to 5 b-4 (see the broken line portion in FIG. 3) is elongated in the Z-axis direction. It is desirable to set the characteristics of 126 and the condenser lens 6. Accordingly, the number of pixel electrodes contributing to the diffraction of the signal light can be increased, so that the diffraction efficiency can be further increased. Further, by reducing the pixel width of each of the LCOSs 5a-1 to 5a-4, 5b-1 to 5b-4, the phase difference between adjacent pixels can be reduced, thereby increasing the diffraction angle for each LCOS. Can be suppressed.

  Next, the optical path between the light input / output units 1 and 2 and the condenser lens 6 will be described. First, referring to FIG. 1, the arrangement direction of the optical fiber port groups 110 and 120 (hereinafter referred to as the port arrangement direction), that is, between the light input / output units 1 and 2 and the condenser lens 6 as viewed from the Z-axis direction. The optical path will be described.

  The optical paths of the signal lights L1 to L5 and L11 to L15 input to and output from the plurality of optical input / output units 1 and 2 (hereinafter referred to as input / output optical paths) are solid arrows in FIG. The optical path is as shown by the broken line arrows. In the following, the input / output optical path described with reference to FIG. 1 is viewed from the Z-axis direction.

  As shown in FIG. 1, the input / output optical paths of the light input / output units 1 and 2 are substantially overlapped when viewed from the Z-axis direction.

  Next, referring to FIG. 2, the optical fiber port groups 110 and 120 are inserted between the light input / output units 1 and 2 and the condenser lens 6 as viewed from the direction perpendicular to the port arrangement direction, that is, the X-axis direction. The output optical path will be described. In the following, the input / output optical path described with reference to FIG. 2 is viewed from the X-axis direction.

  As indicated by solid line arrows and broken line arrows in FIG. 2, the light input / output optical paths on the side of the plurality of light input / output units 1 and 2 with respect to the condenser lens 6 are perpendicular to the port arrangement direction of the optical fiber port groups 110 and 120. Viewed from the right direction (X-axis direction), the optical fiber ports in the same optical fiber port group are parallel to each other, and the optical fiber ports of different optical fiber port groups are not parallel to each other. That is, the input / output optical paths of the optical input / output units 1 and 2 are parallel between the optical fiber ports 111 to 115 in one optical fiber port group 110, and each of the optical fiber port groups 120 in the other optical fiber port group 120. Parallel between the optical fiber ports 121 to 125. Further, these input / output optical paths are non-parallel between the optical fiber ports 111 to 115 of the different optical fiber port groups 110 and 120 and the optical fiber ports 121 to 125.

  Also, among the input / output optical paths of the optical input / output units 1 and 2, the input / output optical path corresponding to the optical fiber port group 110 and the input / output optical path corresponding to the optical fiber port group 120 are as shown in FIG. They intersect each other at or near the condenser lens 6. Specifically, the optical paths of each light input from each of the two different optical fiber port groups 110 and 120 in the plurality of light input / output units 1 and 2 intersect each other at or near the condenser lens 6. To do. In FIG. 2, the optical paths of the lights input from the two different optical fiber port groups 110 and 120 among the plurality of light input / output units 1 and 2 intersect on the condenser lens 6. Yes.

  FIG. 5 is a diagram illustrating the relationship between the signal light L1 and the signal light L11. In FIG. 5, the thick solid line indicates the optical path of the signal light L1, and the thin solid line indicates the spread of the beam of the signal light L1. A thick broken line indicates the optical path of the signal light L11, and a thin broken line indicates the spread of the beam of the signal light L11. In the example of FIG. 5, the beam divergence angles of the signal light L1 and the signal light L11 are substantially the same at θ, and the angle formed by the beams of the signal light L1 and the signal light L11 is, for example, about 2θ. Is set.

In general, a position where the radiation intensity of the Gaussian beam is 1 / e ² is called a beam spot radius. In particular, when the spot radius at the beam waist is w0, the beam divergence angle is θ ′ = λ / πw0. In general, it is sufficient that the Gaussian beam propagates with an aperture diameter that is approximately twice the spot radius. The beam divergence angle in the present embodiment is defined as θ = aθ ′, taking into consideration the characteristics of the wavelength selective switch and thinning, and an appropriate positive coefficient a. In the present embodiment, the value of a is assumed to be about 1.2 to 2 times.

  Note that FIG. 5 shows the relationship between the signal light L1 and the signal light L11, but other signal lights have the same relationship. That is, the arbitrary signal light of the signal lights L1 to L5 input to and output from the optical fiber port group 110 and the arbitrary signal light of the signal lights L11 to L15 input to and output from the optical fiber port group 120 are FIG. 5 has the relationship. As shown in FIG. 5, the signal light L1 and the signal light L11 each have a spread angle of θ. The condensing lens 6 condenses and outputs the input signal light L1 and signal light L11. For this reason, the signal light L1 and the signal light L11 have the maximum beam diameter in the vicinity of the condenser lens 6. Therefore, the width in the switch axis direction can be minimized by setting the signal light L1 and the signal light L11 to intersect in the vicinity of the condenser lens 6 so as to overlap each other. Further, when the spread angle of the signal light is approximately θ, by setting the angle between the signal light beams to be 2θ or more, even if the spread of the beam is taken into consideration, the optical system The width in the switch axis direction can be reduced. In particular, when the angle between the signal light beams is set to be approximately 2θ, the angle formed between both ends of the signal light beam is approximately “0” (become parallel) as shown in FIG. Therefore, the width of the optical system in the switch axis direction can be minimized.

  4, the prism 4 refracts the optical paths of the signal light L1 to L5 and the signal light L11 to L15 inward, and the signal light L2 positioned at both ends in the switch axis direction by the signal light L1 and The signal light L5 is divided into two equal parts, and the signal light L12 and the signal light L15 located at both ends in the switch axis direction are divided into two equal parts by the signal light L11. And the crosstalk characteristics between the ports can be improved. That is, in the LCOS which is the optical path switching units 5a and 5b, when the angle for switching is increased, the diffraction efficiency is reduced and higher-order diffraction is generated, and higher-order diffracted light is incident on an unintended port. As a result, the crosstalk between the ports decreases. Therefore, as shown in FIG. 4, by setting the optical path of the Com port to bisect the maximum angle optical path located at both ends, the angle of diffraction at the time of switching is minimized, and as a result Loss during diffraction can be reduced and crosstalk characteristics can be improved.

(B) Description of Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. 6 and 7, the same reference numerals are given to the portions corresponding to those in FIGS. 1 and 2, and the description thereof is omitted. 6 and 7, compared with FIGS. 1 and 2, the polarization manipulation optical system 9 is replaced with a polarization manipulation optical system 12 configured by a rutile prism or the like, and the polarization manipulation optical system 12. Is moved between the cylindrical lens 7a and the anamorphic prism 7b constituting the anamorphic optical system 7. Other configurations are the same as those in FIGS. 1 and 2. As described above, even when the polarization manipulating optical system 12 is moved to a position away from the prism 11, the same operation as that of the first embodiment can be expected, and the first embodiment and the first embodiment can be expected. Similar effects can be expected.

(C) Description of Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIGS. 8 to 11, parts corresponding to those in FIGS. 6 and 7 are denoted by the same reference numerals and description thereof is omitted. 8 to 11, compared with FIGS. 6 and 7, the prism 4 is replaced with the prism 20, and the optical path operation unit 5 is moved from a position orthogonal to the optical axis 6 a to a parallel position. Other configurations are the same as those in FIGS. 6 and 7. Here, as shown in FIG. 10, the prism 20 reflects the incident signal light at a substantially right angle by the surface 20a and refracts the signal light inward by the bottom portion 20b having two different refractive powers. L1 is adjusted to bisect the angle formed by the signal light L2 and the signal light L5, and the signal light L11 is adjusted to bisect the angle formed by the signal light L12 and the signal light L15. In FIG. 10, only the signal lights L1, L2, and L5 and the signal lights L11, L12, and L15 are shown to simplify the description.

  A signal line for controlling the LCOS is connected to the optical path operation unit 5, and such a signal line extends from the end of the optical path operation unit 5 in the Z-axis direction in the example of FIG. It has become. The optical switch 10 is housed in a housing (not shown), and a plurality of housings are used in a rack. In such a usage pattern, when the above-described signal line is taken out from the housing, it is desirable to draw out the signal line in the Y-axis direction or the X-axis direction in the example of FIG. However, in the example of FIG. 7, in order to pull out the signal line from the housing, it is necessary to bend the signal line extended from the optical path operation unit 5 in the Z-axis direction in the Y-axis direction or the X-axis direction. For this reason, in the example of FIG. 7, it is necessary to route the signal line substantially at a right angle, so that the mounting operation becomes complicated and it is necessary to secure a space for routing the signal line at a substantially right angle. On the other hand, in the case of the embodiment shown in FIGS. 8 and 9, since the signal line extending in the Y-axis direction from the end of the optical path operation unit 5 can be pulled out from the housing as it is, as in the case of FIG. Since it is not necessary to draw the wire at a substantially right angle, it is possible to simplify the mounting of the signal line and reduce the accommodation space, thereby reducing the size of the device.

  Since the operations and effects of the third embodiment shown in FIGS. 8 to 10 are the same as those of the first embodiment described above, the detailed description of the operations is omitted.

  In the third embodiment shown in FIGS. 8 to 10, as shown in FIG. 10, the prism 20 refracts the signal light inward by the bottom 20b having two different refractive powers, and the signal light L1 is the signal light. The angle formed by L2 and the signal light L5 is adjusted to bisect, and the signal light L11 is adjusted to bisect the angle formed by the signal light L12 and the signal light L15. Instead of providing the bottom portion 20b, an optical structure having two different refractive powers may be provided on the surface of the optical path operation unit 5. FIG. 11 is a diagram showing a cross-sectional structure of the optical path operation unit 5 provided with optical structures having two different refractive powers. In the example of FIG. 11, the optical path of the signal light can be refracted inward by shaping the cross-sectional shape of the cover glass 51 provided to protect the optical path operation unit 5 into a substantially triangular shape. Further, by adjusting the shape of the cover glass 51, the signal light L1 bisects the angle formed by the signal light L2 and the signal light L5, and the signal light L11 sets the angle formed by the signal light L12 and the signal light L15 by two. It can be set to divide equally.

(D) Explanation of 4th Embodiment Next, 4th Embodiment of this invention is described with reference to FIG. 12 and FIG. 12 and 13, the same reference numerals are given to the portions corresponding to those in FIGS. 8 and 9, and the description thereof is omitted. In FIGS. 12 and 13, compared with FIGS. 8 and 9, the condenser lens 6 is excluded and cylindrical lenses 21 and 22 are added. Other configurations are the same as those in FIGS. 8 and 9. Here, as shown in FIG. 13, the cylindrical lens 21 refracts the signal light in the switch axis direction (Z-axis direction) and outputs it. Further, as shown in FIG. 12, the cylindrical lens 22 refracts the signal light in the chromatic dispersion axis direction (X-axis direction) and outputs it. In addition, as shown in FIG. 13, the optical path groups possessed by each of the plurality of light input / output units 1 and 2 intersect so as to substantially overlap in the cylindrical lens 21 or in the vicinity thereof. Assuming that the focal length of the cylindrical lens 22 is f, the wavelength dispersive element 8 is disposed at a position where the light propagation length is separated from the cylindrical lens 22 by f, and the light operating unit 5 has a light propagation length from the cylindrical lens 22. It is arranged at a position separated by f. On the other hand, assuming that the focal length of the cylindrical lens 21 is f ′, the optical operation unit 5 is arranged at a position where the light propagation length is separated from the cylindrical lens 21 by f ′, and the wavelength dispersion element 8 is the light propagation from the cylindrical lens 21. It is arranged at a position whose length is shorter than f ′. Here, f ′> f, and f ′ is larger than the focal length f of the cylindrical lens 22. For this reason, since the distance from the cylindrical lens 21 to the optical path manipulating unit 5 can be increased, the diffraction angle in the optical path manipulating unit 5 is reduced to reduce loss during diffraction and to improve crosstalk characteristics. can do.

  Since the operation and effects of the fourth embodiment shown in FIGS. 12 and 13 are the same as those of the first embodiment described above, the detailed description of the operation is omitted.

(E) Description of Fifth Embodiment Next, a fifth embodiment of the present invention will be described with reference to FIGS. 14 and 15. 14 and 15, the same reference numerals are given to the portions corresponding to those in FIGS. 8 and 9, and the description thereof is omitted. 14 and 15, compared with FIGS. 8 and 9, the prism 11 is moved to the subsequent stage of the wavelength dispersion element 8, the polarization operation optical system 12 is moved to the subsequent stage of the optical input / output units 1 and 2, and Relay lens systems 23 and 24 are added before and after the morphic prism 7b. Other configurations are the same as those in FIGS. 8 and 9. Here, the relay lens systems 23 and 24 transmit the images formed by the collimator lens groups 116 and 126 to the rear at the same magnification or n times. The signal light output from the relay lens 23 forms a beam waist (BW2) between the relay lens 23 and the relay lens 24. The signal light output from the relay lens 24 forms a beam waist (BW3) by the wavelength dispersion element 8. Note that the signal light output from the collimator lens groups 116 and 126 forms a beam waist (BW1) in the polarization operation optical system 12 in the example of FIG. The last beam waist BW3 is set to be located in the vicinity of the wavelength dispersion element 8 or after that.

  In the fifth embodiment, since the beam waists BW2 and BW3 are formed after the first beam waist BW1, the signal light formed on the condenser lens 6 is compared with the case of only the beam waist BW1. Since the spot diameter of the focusing lens 6 can be reduced, the width of the condensing lens 6 in the switch axis direction can be reduced, so that the entire apparatus can be reduced in size. That is, when the beam waists BW2 and BW3 are not provided, the signal light spreads at an angle θ according to the distance from the beam waist BW1 and is maximized on the condenser lens 6. However, when the beam waists BW2 and BW3 are provided, the beam spreads from the last beam waist BW3, so that the spot diameter on the condenser lens 6 is made smaller than in the case of only the beam waist BW1. Can do. Further, the spot diameter can be further reduced by arranging the last beam waist BW3 in the vicinity of the wavelength dispersion element 8 or after that.

  The operation and effects of the fourth embodiment shown in FIGS. 14 and 15 are the same as those of the first embodiment described above, and thus detailed description of the operation is omitted.

(F) Description of Sixth Embodiment Next, a sixth embodiment of the present invention will be described with reference to FIGS. 16 and 17. 16 and 17, the same reference numerals are given to the portions corresponding to those in FIGS. 12 and 13, and the description thereof is omitted. 16 and 17, compared with FIGS. 12 and 13, the light input / output units 1 and 2 have five optical systems (fiber port group and collimator lens group), but have three optical systems. In addition, an input / output port 3 having three optical systems is newly added. Further, the prism 11 is replaced with the prism 13, the prism 20 is replaced with the prism 25, and the optical path operating unit 5 is replaced with the optical path operating unit 50. Other configurations are the same as those in FIGS. 12 and 13.

  Here, the optical input / output unit 1 supports an optical fiber port group 110 including three optical fiber ports, a collimator lens group 116 including three collimator lenses, an optical fiber port 110 to 113, and a collimator lens group 116. And a support part 117 to be provided. The light input / output units 2 and 3 have the same configuration as the light input / output unit 1. The prism 13 allows the signal light output from the light input / output unit 2 to pass through without being refracted, and the signal light output from the light input / output units 1 and 2 is refracted inward (to the optical axis 6a side) and output. To do. The signal lights output from the collimator lens groups 116, 126, and 136 are refracted by the prism 13 and intersect so as to overlap in the cylindrical lens 21 or in the vicinity thereof. The prism 25 refracts the signal light output from the cylindrical lens 22 at a substantially right angle by the surface 25a, the signal light L1 bisects the signal lights L2 and L3 by the bottom 25b, and the signal light L11 becomes the signal lights L12 and L13. Are divided into two equal parts, and the signal light L21 is refracted so as to divide the signal lights L22 and L23 into two equal parts and output. As a result, the signal lights L1, L11, and L21 output from the prism 25 are incident on the optical path switching units 5a, 5b, and 5c, respectively. The optical path switching units 5a, 5b, and 5c reflect at an angle corresponding to the wavelengths of the signal lights L1, L11, and L21. As a result, the optical switch 10 uses the optical path of the signal light input from the optical fiber port 112 that is the Com port of the optical input / output unit 1 to the optical fiber port 111 or the optical fiber port 113 assigned to the wavelength. You can switch to Similarly, the optical path of the signal light input from the optical fiber port 122 which is the Com port of the optical input / output unit 2 can be switched to the optical path leading to the optical fiber port 121 or the optical fiber port 123 assigned to the wavelength. At the same time, the optical path of the signal light input from the optical fiber port 132 which is the Com port of the optical input / output unit 3 can be switched to the optical path to the optical fiber port 131 or the optical fiber port 133 assigned to the wavelength.

  As described above, according to the sixth embodiment, the signal light input from the three light input / output units 1 to 3 can be output from the light input / output unit corresponding to the wavelength. Note that the detailed operation and effects of the sixth embodiment are substantially the same as those of the first embodiment described above, and a description thereof will be omitted.

(G) Description of Modified Embodiment Each of the above embodiments is an example, and it is needless to say that the present invention is not limited to the case described above. For example, in each of the above embodiments, an optical switch including a plurality of optical input / output units of a 1 × 4 optical switch having one input port (Com port) and four output ports has been illustrated. It is not limited to. That is, the number of ports of each of the plurality of optical input / output units included in the optical switch according to the present invention is not limited to five, and may be any number. For example, it may be an optical input / output unit of a 1 × M optical switch in which the number of input ports is “1” and the number of output ports is “M”, or the number of input ports is “N” and the output port It may be an optical input / output unit of an N × 1 optical switch whose number is “1”. Alternatively, a combination of these, that is, an optical input / output unit of an N × M optical switch in which the number of input ports is “N” and the number of output ports is “M” may be used. In this case, the number of optical path switching units provided in the optical path operation unit may be adjusted according to the number of light input / output units. The number of input ports M and the number of output ports N are both integers of 1 or more.

  Further, in each of the above-described embodiments, light is input from the Com port of the optical input / output unit, and light is output from the remaining ports (such as optical fiber ports) other than the Com port. It is not limited to. That is, light may be input from the remaining ports other than the Com port, and light may be output from the Com port.

  Further, in each of the above-described embodiments, a 2-in-1 optical switch having two different optical switch functions in one device or a 3-in-1 optical switch having three different optical switch functions in one device is exemplified. The invention is not limited to this. The number of optical input / output port groups included in the optical switch according to the present invention is not particularly limited to two or three, and may be two or more. That is, the optical switch according to the present invention may be a J (J is an integer of 2 or more) in1 optical switch having a plurality of different optical switch functions (including wavelength selection optical switch functions) in one apparatus. For example, an optical switch or a wavelength selective optical switch provided with the above-described optical input / output units for a total of J may be configured.

  In each of the above-described embodiments, the plurality of optical path switching units are configured by LCOS. However, the present invention is not limited to this, and the plurality of optical path switching units may be configured by MEMS mirrors or DMD (Digital Micro Mirror). Device).

  Furthermore, in each of the above-described embodiments, each port in the optical input / output unit is configured by an optical fiber. However, the present invention is not limited to this, and each port in the optical input / output unit is a light other than an optical fiber such as a quartz waveguide. It may be constituted by a waveguide.

  In each of the above-described embodiments, the light input / output unit 1 and the light input / output unit 2 are configured to be independent. However, they may be accommodated in one common support unit. Further, each of the light input / output unit 1 and the light input / output unit 2 may be accommodated in a plurality of independent support portions. Specifically, the light input / output unit 1 may be housed separately in a plurality of independent support portions, and the light input / output unit 2 may be housed separately in a plurality of independent support portions.

  In each of the above-described embodiments, the number of optical fiber ports is the same between the optical fiber port groups. However, the number of ports in each optical input / output port group is not limited to this, and the number of ports varies between the port groups. It may be.

  In each of the embodiments described above, the plurality of optical fiber port groups are arranged in parallel to the optical axis of the condenser lens when viewed from the direction perpendicular to the port arrangement direction (X-axis direction), and are refracted by the prism. Thus, the beams intersect at the condenser lens 6, but the present invention is not limited to this. That is, the optical input / output port groups included in the optical switch according to the present invention may be arranged non-parallel to each other when viewed from the X-axis direction, and the beams may intersect at the condenser lens 6.

  Further, in each of the above-described embodiments, the condensing lens is disposed in the vicinity of the intersection position of each input / output optical path of a plurality of light input / output units different from each other, but the condensing lens is connected to each light on the optical path operation unit. In consideration of the separation distance between image points and optical characteristics such as a condensing lens, they may be arranged at a position slightly deviated from the intersection position.

  In each of the above-described embodiments, a condensing lens having a single optical axis is used. However, the present invention is not limited to this, and the condensing lens system may be configured by a compound lens system using a plurality of lenses. There may be a plurality of optical axes of the condenser lens system.

  In each of the above-described embodiments, the wavelength dispersion element is configured using a transmission type diffraction grating. However, the present invention is not limited thereto, and the wavelength dispersion element may be configured using a reflection type diffraction grating. In addition, the wavelength dispersion element may be configured using another light dispersion element such as a dispersion prism. In addition, when the wavelength dispersion element is configured by a transmission type diffraction grating, it is not necessary to bend the optical path greatly. Therefore, it is easy to arrange each element constituting the optical switch without interfering with an unintended optical path. is there.

  In each of the above-described embodiments, the center optical fiber port of each optical fiber port group is a Com port, light is input from this Com port, and the remaining optical fiber ports are output ports. The invention is not limited to this. That is, in the present invention, the position of the Com port in the optical input / output port group is not particularly limited.

  Further, in each of the embodiments described above, a plurality of LCOSs that are classified according to the wavelength of light to be optical path operated and by port group (specifically, by optical fiber port) are provided in the optical path operating unit. It is not limited to this. That is, a single LCOS may be provided in the optical path operation unit, and the single LCOS may be classified according to the wavelength and the port group of the light subjected to the optical path operation. In this case, a different optical path switching unit may be configured for each light input / output unit by using a plurality of divided LCOS portions.

  Moreover, although each embodiment mentioned above illustrated the optical switch provided with the wavelength dispersion element 8 which disperse | distributes input light according to a wavelength, this invention is not limited to this. In other words, it does not include the wavelength dispersion element 8, and has a plurality of light input / output units having light input ports and output ports such as optical fiber ports, and a single optical path switching unit (for example, LCOS) for each light input / output unit. An optical switch that includes an optical path operation unit and optical elements such as a condensing lens and an anamorphic optical system as appropriate may be used.

  Further, the present invention is not limited by the above embodiment. What comprised each component of each said embodiment combining suitably is also contained in this invention. In addition, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the present invention.

1, 2, 3 Optical input / output unit 5, 50 Optical path operation unit 5a, 5b, 5c Optical path switching unit 5a-1 to 5a-4, 5b-1 to 5b-4, 5c-1 to 5c-4 LCOS
6 condensing lens 6a optical axis 7 anamorphic optical system 7a, 7b anamorphic prism 8 wavelength dispersion element 9 polarization manipulation optical system 11 prism 12 polarization manipulation optical system 10 switch 110, 120, 130 optical fiber port group 111 ˜115, 121˜125, 131˜133 Optical fiber ports 117, 127, 137 Support portions L1˜L5, L11˜L15, L21˜L23 Signal light P1, P2, P3 Imaging point

Claims (15)

A plurality of optical input / output units each having a port group composed of a plurality of ports for inputting or outputting light;
An optical path operating unit having a plurality of optical path switching units for switching each optical input / output unit to an optical path directed to an output port in the same port group, an optical path of light input from an input port in the port group;
Light input from the plurality of light input / output units is condensed on the plurality of optical path switching units for each port group, and light input from the plurality of optical path switching units is collected for each of the plurality of light for each port group. A condenser lens optically coupled to the input / output unit;
A wavelength dispersion element that wavelength-disperses each light input from the plurality of light input / output units in a direction substantially perpendicular to a switch axis direction that is an arrangement direction of the light input / output units;
Optical switch and a light path groups to each other of the light input from the port group, each of said plurality of light input and output section has cross so that at least partially overlaps Te wherein the condenser lens smell.   The relationship of H1 ≧ H2 is established when the aperture diameter of the wavelength dispersion element in the switch axis direction is H1, and the aperture diameter of the condenser lens in the switch axis direction is H2. The optical switch according to 1.   3. The optical switch according to claim 1, wherein the wavelength dispersion element is disposed at a position separated from the condenser lens by a focal length of the condenser lens. An optical element that is disposed closer to the light input / output unit than the condenser lens and has a plurality of different refractive powers in the switch axis direction;
The optical element refracts an optical path group of light input or output from the port group at a different angle for each optical path group by the plurality of different refractive powers, and at least a part of the optical element overlaps the condenser lens. The optical switch according to claim 1, wherein the optical switches are crossed .   The optical switch according to claim 4, wherein the optical element having a plurality of different refractive powers in the switch axis direction is a prism having a plurality of different refractive powers in the switch axis direction.   6. The optical switch according to claim 4, wherein the optical elements having a plurality of different refractive powers in the switch axis direction are disposed in the vicinity of the wavelength dispersion element.   The optical switch according to claim 6, wherein the last beam waist existing on the light input / output unit side of the condenser lens is in the vicinity of the wavelength dispersion element or after.   6. The optical switch according to claim 4, wherein the optical element having a plurality of different refractive powers in the switch axis direction has a light propagation length from the light input / output unit of approximately 50 mm or less.   6. The optical switch according to claim 4, wherein an aperture diameter of the condensing lens in the switch axis direction is about 15 mm or less.   The angle formed by the optical path when any two port groups are selected when the beam divergence angle of the light input from the light input / output unit is θ is approximately 2θ. 5. The optical switch according to 5.   5. The angle formed by the optical path when any two port groups are selected when the beam divergence angle of light input from the light input / output unit is θ is approximately 2θ or more. Or the optical switch of 5.   An optical element having a plurality of different refractive powers in the switch axis direction is disposed in the vicinity of the optical path operation unit, and adjusts an incident angle of light incident on the optical path switching unit for each port group. The optical switch according to claim 1.   The optical switch according to claim 12, wherein the optical element having a plurality of different refractive powers in the switch axis direction is a prism having a plurality of different refractive powers in the switch axis direction.   When a port to which light is input from the outside to the port group is a Com port, the light of the Com port specularly reflected by the optical path switching unit is incident light from ports located at both ends of the port group. 14. The optical switch according to claim 12, wherein the angle formed is substantially bisected. The optical switch according to claim 12 or 13, wherein the optical path switching unit is configured by LCOS (Liquid Crystal on Silicon).

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