Source: http://www.google.com/patents/US7010200?dq=6,249,089
Timestamp: 2016-12-10 17:12:37
Document Index: 246021902

Matched Legal Cases: ['art 38', 'arts 34', 'arts 35', 'arts 34', 'arts 35', 'arts 35']

Patent US7010200 - Light-beam switching/adjusting apparatus and manufacturing method thereof - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsThe light guide substrate 2 has mirror receiving grooves 24 and light guides. The light guides conduct light that is input into the input ports to selected output ports in accordance with the advance and retraction of the mirrors 31 with respect to the grooves 24. The actuator substrate 4 has mirrors...http://www.google.com/patents/US7010200?utm_source=gb-gplus-sharePatent US7010200 - Light-beam switching/adjusting apparatus and manufacturing method thereofAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS7010200 B2Publication typeGrantApplication numberUS 10/500,086PCT numberPCT/JP2002/013003Publication dateMar 7, 2006Filing dateDec 12, 2002Priority dateDec 26, 2001Fee statusLapsedAlso published asCN1608223A, CN100376918C, EP1486814A1, EP1486814A4, US20050018955, WO2003056380A1Publication number10500086, 500086, PCT/2002/13003, PCT/JP/2/013003, PCT/JP/2/13003, PCT/JP/2002/013003, PCT/JP/2002/13003, PCT/JP2/013003, PCT/JP2/13003, PCT/JP2002/013003, PCT/JP2002/13003, PCT/JP2002013003, PCT/JP200213003, PCT/JP2013003, PCT/JP213003, US 7010200 B2, US 7010200B2, US-B2-7010200, US7010200 B2, US7010200B2InventorsKeiichi Akagawa, Yoshihiko Suzuki, Tohru Ishizuya, Junji Suzuki, Katsuhiko Kurumada, Masatoshi Kanaya, Toshiaki TamamuraOriginal AssigneeNikon Corporation, Ntt Electronics CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (25), Non-Patent Citations (2), Classifications (19), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetLight-beam switching/adjusting apparatus and manufacturing method thereof
US 7010200 B2Abstract
The light guide substrate 2 has mirror receiving grooves 24 and light guides. The light guides conduct light that is input into the input ports to selected output ports in accordance with the advance and retraction of the mirrors 31 with respect to the grooves 24. The actuator substrate 4 has mirrors 31 and actuators which place the mirrors 31 in a state in which the mirrors are drawn in toward the substrate 4, or a state in which the mirrors protrude from the substrate 4. The light guide substrate 2 and actuator substrate 4 are aligned using alignment marks and joined with a spacer 3 interposed so that the mirrors 31 retract from the grooves 24 when the mirrors 31 are drawn in toward the substrate 4, and so that the mirrors 31 advance into the grooves 24 when the mirrors 31 protrude from the substrate 4. This alignment is performed in a state in which all of the mirrors 31 are drawn in toward the substrate 4. Images(16) Claims(22)
The present invention relates to a light beam switching and adjustment device used to perform light beam light path conversion and adjustment of the amount of transmission in (for example) optical communications networks, optical switching systems or the like, and a method for manufacturing the same.
Light beam switching and adjustment devices used for light path conversion are necessary in optical communications systems, and in recent years, matrix light beam switching and adjustment devices used to perform light path switching among a plurality of inputs and outputs have become especially important. For example, such matrix light beam switching and adjustment devices perform actions such as the transmission of light signals from one of numerous parallel input optical fibers to one of numerous parallel output optical fibers; a light beam switching and adjustment device such as that disclosed in Japanese Patent Application Kokai No. 2001-142008 is known as a concrete example of such a device.
FIG. 17 shows diagrams used to illustrate an example of the construction of a conventional light beam switching and adjustment device using MEMS technology. FIG. 17( a) is a plan view of this light beam switching and adjustment device, and FIG. 17( b) is a sectional view along line A–A′ in FIG. 17( a).
Specifically, in a state in which the corresponding insertion plate 305 is inserted into the corresponding slit 303, the light beam that enters this slit 303 from the first light guide core 302 a is reflected by the insertion plate 305, and is therefore coupled with the end surface of the second light guide core 302 b. On the other hand, in a state in which this insertion plate 305 is withdrawn from the slit 303, the light beam that enters the slit 303 from the first light guide core 302 a is coupled “as is” with the end surface of the facing third light guide core 302 c. In this way, switching of the light paths of the light beams is performed, so that a switching action is realized.
The present invention was devised in order to solve the problems described above. The first object of the present invention is to provide a light beam switching and adjustment device which can be manufactured easily and with a good yield as a result of the alignment of the mirrors and mirror receiving recesses being facilitated, and a method for manufacturing this light beam switching and adjustment device. Furthermore, the second object of the present invention is to provide a light beam switching and adjustment device in which discrimination of the positional relationship between the insertion plates and the slits formed in the light guide cores, and the discrimination of the insertion positions of the insertion plates inside the slits, are easy.
FIG. 1 is a schematic plan view which shows in model form a light beam switching and adjustment device according to one embodiment of the present invention.
FIG. 2 is a schematic sectional view along line A–B in FIG. 1, and shows a state in which all of the mirrors have advanced into the grooves of the light guide substrate.
FIG. 3 is a schematic sectional view along line A–B in FIG. 1, and shows a state in which all of the mirrors have withdrawn from the grooves of the light guide substrate.
FIG. 7 is a schematic sectional view along line X1–X2 in FIG. 6.
FIG. 8 is a schematic sectional view along line Y1–Y2 in FIG. 6.
FIG. 15 shows diagrams which are used to illustrate an example of the construction of the light beam switching and adjustment device of the present invention; FIG. 15( a) is a plan view of this device, and FIG. 15( b) is a sectional view along line A–A′ in FIG. 15( a).
FIG. 17 shows diagrams which are used to illustrate an example of construction of a conventional light beam switching and adjustment device using MEMS technology; FIG. 17( a) is a plan view of this light beam switching and adjustment device, and FIG. 17( b) is a sectional view along line A–A′ in FIG. 17( a).
The light beam switching and adjustment device of the present invention, and method for manufacturing the same, will be described below with reference to the figures.
FIG. 2 is a schematic sectional view along line A–B in FIG. 1, and shows a state in which all of the mirrors 31 have advanced into the grooves 24 of the light guide substrate 2. FIG. 3 is a schematic sectional view along line A–B in FIG. 1, and shows a state in which all of the mirrors 31 have withdrawn from the grooves 24 of the light guide substrate 2. FIG. 4 is a schematic plan view which shows in model form the assembly of the substrate 1, light guide substrate 2, light input optical fibers 11, and light output optical fibers 12 and 13 in the manufacturing process of the light beam switching and adjustment device shown in FIG. 1.
As is shown in FIGS. 2 through 4, the light guide substrate 2 has three input ports 21 in the left end surface in FIG. 4, three output ports 22 in the right end surface in FIG. 4, three output ports 23 in the lower end surface in FIG. 4, 3×3 grooves 24 used as mirror receiving recesses which are formed in the −Z-side surface of the light guide substrate 2, and light guides 25.
The light guides 25 are formed so that these light guides conduct the light that is input into the three input ports 21 to selected output ports in accordance with the advance (see FIG. 2) and retraction (see FIG. 3) of 3×3 individual mirrors 31 (described later) corresponding to the 3×3 individual grooves 24. In the present embodiment, the light guides 25 are formed in the form of a 3×3 matrix, and the grooves 24 are respectively formed at the 3×3 intersection points of this matrix. The number of 3×3 described above is merely an example; the present invention is not limited to this number. In cases where a construction with the form of a two-dimensional matrix is used, this number may be set in general terms at M×N (M and N are integers of 2 or greater) instead of 3×3. For example, a case in which this number is 100×100 is the same in principle. Of course, in the present invention, it is not always necessary to use a two-dimensional matrix-form construction. The respective ports 21, 22 and 23 constitute the end portions of the light guides 25 appearing at the end surfaces of the light guide substrate 2. Furthermore, the light guides 25 are constructed from core layers, cladding layers and the like; the construction of these light guides 25 is universally known.
Next, the actuator substrate 4 will be described with reference to FIGS. 5 through 10. FIG. 5 is a schematic plan view which shows the actuator substrate 4 in model form. Furthermore, in FIG. 5, the actuators 32, wiring patterns, driving circuit and the like are omitted. FIG. 6 is a schematic enlarged plan view which shows one of the mirrors 31 and one of the actuators 32 that supports and drives this mirror 31 in model form. FIG. 7 is a schematic sectional view along line X1–X2 in FIG. 6. FIG. 8 is a schematic sectional view along line Y1–Y2 in FIG. 6. FIG. 9 is a schematic sectional view corresponding to FIG. 7, and shows a state in which the mirror 31 is held in a position that is relatively close to the +Z-side surface of the actuator substrate 4 (second position, which is a position on the +Z-side surface of the actuator substrate 4 in the present embodiment; this will be referred to below as a “state in which the mirror 31 is drawn in toward the substrate 4”). Incidentally, FIG. 7 shows a state in which the mirror 31 has returned to a position (first position) that is relatively distant from the +Z-side surface of the actuator substrate 4 (this will be referred to below as a “state in which the mirror 31 protrudes from the substrate 4”). FIG. 10 is an electrical circuit diagram which shows the circuit mounted on the actuator substrate 4.
The actuator substrate 4 has 3×3 micromirrors 31 and one or more actuators 32 which are disposed in positions corresponding to these mirrors 31 so that these actuators support the corresponding mirrors 31, and which position these corresponding mirrors 31 on the side of the +Z surface of the actuator substrate 4 (i.e., on the +Z side of the substrate 4) in a first position (see FIG. 7) that is relatively far from this surface or in a second position (see FIG. 9) that is relatively close to this surface, in accordance with signals. As is shown in FIG. 5, the 3×3 mirrors 31 are disposed in positions corresponding to the 3×3 grooves 24 in the light guide 25.
In the present embodiment, both end portions of each movable plate 33 in the direction of the X axis are mechanically connected to the peripheral portions of the recessed part 38 in the substrate 4 via the respective flexure parts 34 a and 34 b (acting as spring parts that possess springiness) and anchor parts 35 a and 35 b in that order. The flexure parts 34 a and 34 b and anchor parts 35 a and 35 b are each constructed from a lower-side insulating film 36 and an upper-side metal film 37 that extend “as is” as continuations of the movable plate 33. In the anchor parts 35 a and 35 b, the upper-side metal films 37 are respectively electrically connected to specified locations on the substrate 4 via holes (not shown in the figures) formed in the lower-side insulating films 36.
The mirrors 31 are fastened to the upper surfaces of the movable plates 33 in an upright attitude. The orientation of the reflective surfaces of the mirrors 31 is set so that the normal of each mirror 31 forms an angle of 45° with the X axis in a plane parallel to the XY plane. Of course, this orientation may be appropriately altered in accordance with the disposition of the light guides 25.
In a state in which the mirrors 31 have returned to the first positions on the side of the substrate 4 (i.e., a state in which the mirrors 31 protrude from the substrate 4), as is shown in FIG. 7, the incident light advancing in the direction of the X axis is reflected by the mirrors 31 and advances toward the front with respect to the plane of the page in FIG. 7. In a state in which the mirrors 31 are positioned in the second positions (i.e., a state in which the mirrors 31 are drawn in toward the substrate 4), as is shown in FIG. 9, the incident light advancing in the direction of the X axis is not reflected by the mirrors 31, and passes through “as is” to form emitted light.
In FIGS. 7 and 9, the incident light that reaches the positions of the mirrors 31 is shown as though this light were propagated through space. However, as a result of the light guide substrate 2 and actuator substrate 4 being aligned and joined with a spacer 3 interposed as shown in FIGS. 2 and 3, this incident light, after being guided by the light guides 25 of the light guide substrate 2 so that this light reaches the interiors of the grooves 24 in the light guide substrate 2, is guided to the light guide 25 in the direction in question after being either reflected or allowed to pass through “as is” by the mirrors 31 according to whether the mirrors 31 are positioned in the first or second positions.
In the present embodiment, as is shown in FIG. 3, the thickness of the spacer 3 is set so that the second positions of the respective mirrors 31 are positions in which the mirrors are completely retracted from the grooves 24. As is shown in FIG. 11, the spacer 3 is constructed in the form of a frame and disposed so that this spacer 3 surrounds the area in which all of the mirrors 31 are distributed. FIG. 11 shows the spacer 3; FIG. 11( a) is a plan view, and FIG. 11( b) is an arrow view along line X3–X4 in FIG. 11( a).
Of course, even if the circuit construction described above in which the NOR gates NV1 through NV3 and NH1 through NH3 and the terminals V1 and H1 are excluded is used, a state can be created in which all of the mirrors 31 are drawn in toward the substrate 4 by supplying respective specified signals to a total of eight terminals, i.e., the terminals C1, C2, VA1, VA2, HA1 and HA2, the clamping voltage VC terminal, and the ground terminal. In this case, however, an increase in the number of terminals that must be used cannot be avoided. In particular, when the number of mirrors 31 increases, there is also a corresponding increase in the number of address terminals; as a result, there is a great increase in the number of terminals that must be used in order to place all of the mirrors 31 in a state in which the mirrors are drawn in toward the substrate 4. For example, in cases where the number of light input optical fibers 11, the number of light output optical fibers 12, and the number of light output optical fibers 13 are all 64, the number of mirrors 31 is 64×64. Since 64=26, the total number of address terminals required is 12, i.e., 6 horizontal and 6 vertical.
In this case, in order to place all of the mirrors 31 in the state shown in FIG. 9 using the circuit construction in which the NOR gates NV1 through NV3 and NH1 through NH3 and the terminals V1 and H1 are removed, it is necessary to supply signals to 12 address terminals in addition to the terminals C1 and C2, the clamping voltage VC terminal and the ground terminal, so that signals must be supplied to a total of 16 terminals. On the other hand, if a circuit construction which uses the NOR gates NV1 through NV3 and NH1 through NH3 and the terminals V1 and H1 is employed as in the present embodiment, even if the number of mirrors 31 is 64×64, all of the mirrors 31 can be placed in a state in which the mirrors are drawn in toward the substrate 4 merely by supplying signals to 6 terminals regardless of the number of mirrors 31.
Here, the relationship between the actuator substrate 4 and the relay substrate 5 will be described not only with reference to FIGS. 1 through 3, but also with reference to FIG. 12. FIG. 12 comprises diagrams which show (in model form) the assembly of the actuator substrate 4 and relay substrate 5 in the manufacturing process of the light beam switching and adjustment device shown in FIG. 1. FIG. 12( a) is a schematic plan view as seen from the +Z side, FIG. 12( b) is an arrow view along line Y3–Y4 in FIG. 12( a), and FIG. 12( c) is a schematic plan view as seen from the −Z side.
The conditions of this alignment are shown in FIG. 14. FIG. 14 is a schematic sectional view which shows (in model form) the conditions of the alignment of the actuator substrate 4 and the light guide substrate 2; this figure corresponds to FIGS. 2 and 3. This alignment is performed in a state in which all of the mirrors 31 are drawn in toward the substrate 4 as a result of the specified signals described above being supplied to the lead terminals 45 in the assembly shown in FIG. 12 from a voltage application circuit 51 via lead wires 52 as shown in FIG. 13. FIG. 13 shows diagrams which illustrate the conditions of voltage application to the assembly shown in FIG. 12; FIG. 13( a) is a schematic plan view as seen from the +Z side, and FIG. 13( b) is an arrow view along line Y5–Y6 in FIG. 13( a). Since alignment is performed in a state in which all of the mirrors 31 are drawn in toward the substrate 4, even if the actuator substrate 4 is lowered downward in FIG. 14 in a state in which the position of the actuator substrate 4 in the left-right direction in FIG. 14 is shifted, the system will be regulated in a state in which the actuator substrate 4 contacts the spacer 3 before the mirrors 31 strike portions other than the grooves 24 in the light guide substrate 2 (this is also seen from FIG. 3). In particular, this effect is ensured by the disposition of the spacer 3 so that this spacer 3 surrounds the region in which the mirrors 31 are distributed on the actuator substrate 4 as shown in FIG. 11. As a result, a situation can be prevented in which the mirrors 31 collide with other locations and are damaged; therefore, the manufacturing yield is improved. Such a complete damage preventing effect that prevents damage to the mirrors 31 during this alignment is obtained both as a result of the fact that all of the mirrors 31 are in a state in which the mirrors are drawn in toward the substrate 4 during alignment, and as a result of the fact that the spacer 3 is interposed. However, even if only one of these two means is used, damage to the mirrors 31 is far less likely than in cases where neither of these means is used.
FIG. 15 shows diagrams which are used to illustrate an example of the construction of the light beam switching and adjustment device of the present invention; FIG. 15( a) is a plan view of this device, and FIG. 15( b) is a sectional view along line A–A′ in FIG. 15( a). Furthermore, in FIGS. 15 through 17, the same constituent elements are labeled with the same symbols, and a description in each figure may be omitted.
Specifically, as is shown in FIG. 15( a), in a state in which the insertion plate 103 b is withdrawn from the slit 102 b, for example, the incident light beam 104 a that enters the slit 102 b from the first light guide core 101 a coupled to the incident-side optical fiber 105 is coupled “as is” with the end surface of the facing light guide core 101 a to form a transmitted light beam 104 c. On the other hand, in a state in which the insertion plate 103 a is inserted into the slit 102 a, the incident light beam 104 a is reflected by the insertion plate 103 a, thus forming a reflected light beam 104 b; this light beam is coupled with the end surface of the light guide core 101 b, so that the light path of the light beam is switched, thus realizing a switching operation. Furthermore, an attenuation operation that attenuates the intensity of the transmitted light can also be realized by adjusting the insertion positions (insertion depths) of the insertion plates 103 inside the slits 102.
In such a light beam switching and adjustment device, it is necessary to suppress the light loss of the transmitted light beams and reflected light beams in the slits with respect to the incident light beams to an extremely small value. For example, in order to lower the light loss in the slits to approximately 0.5 dB or less, it is desirable to set the slit width at 10 μm or less. Accordingly, in the light beam switching and adjustment device of the present invention as well, in cases where light guide cores and slits that have a width of 10 μm or less are formed, a so-called “PLC (planar light wave circuit)” technique is employed in which quartz is deposited on the surface of a silicon substrate, and this quartz is then etched. Furthermore, besides a silicon substrate, a glass substrate or the like may also be used as the core supporting substrate of the light beam switching and adjustment device of the present invention.
For example, the light beam switching and adjustment device of the present invention can be utilized to perform the light path switching of light beams and adjustment of the amount of transmitted light in optical communication systems.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS5587341Oct 18, 1994Dec 24, 1996Hitachi, Ltd.Process for manufacturing a stacked integrated circuit packageUS5841917Jan 31, 1997Nov 24, 1998Hewlett-Packard CompanyOptical cross-connect switch using a pin grid actuatorUS5960131Feb 4, 1998Sep 28, 1999Hewlett-Packard CompanySwitching element having an expanding waveguide coreUS6122174Jun 2, 1999Sep 19, 2000Intel CorporationMethod of accessing the circuitry on a semiconductor substrate from the bottom of the semiconductor substrateUS6195478 *Sep 28, 1999Feb 27, 2001Agilent Technologies, Inc.Planar lightwave circuit-based optical switches using micromirrors in trenchesUS6320126Jul 14, 1998Nov 20, 2001Texas Instruments IncorporatedVertical ball grid array integrated circuit packageUS6360036Jan 14, 2000Mar 19, 2002Corning IncorporatedMEMS optical switch and method of manufactureUS6404942 *Oct 19, 1999Jun 11, 2002Corning IncorporatedFluid-encapsulated MEMS optical switchUS6420782Jan 6, 2000Jul 16, 2002Texas Instruments IncorporatedVertical ball grid array integrated circuit packageUS6445840 *Jan 13, 2000Sep 3, 2002Omm, Inc.Micromachined optical switching devicesUS6449406 *Jan 13, 2000Sep 10, 2002Omm, Inc.Micromachined optomechanical switching devicesUS6463190Mar 6, 2000Oct 8, 2002Japan Aviation Electronics Industry LimitedOptical switch and method of making the sameUS6493482 *Nov 22, 2000Dec 10, 2002L3 Optics, Inc.Optical switch having a planar waveguide and a shutter actuatorUS6643426 *Sep 28, 2000Nov 4, 2003Corning IncorporatedMechanically assisted release for MEMS optical switchUS20020061159 *Jun 14, 2001May 23, 2002Brahim DahmaniOptical switch having an impact printer head actuatorUS20020181852 *Apr 8, 2002Dec 5, 2002Anis HusainMicromachined optomechanical switching cell with parallel plate actuator and on-chip power monitoringEP0961150A2May 26, 1999Dec 1, 1999Lucent Technologies Inc.Micro-opto-electromechanical devices and method thereforEP1099496A1Oct 25, 2000May 16, 2001Acciai Speciali Terni S.p.A.Method and device for reducing heat dissipation of a continuous casting mouldEP1136851A1Mar 23, 2000Sep 26, 2001Corning IncorporatedOptical waveguide with encapsulated liquid upper claddingJP2000258702A Title not availableJP2000258704A Title not availableJP2001142008A Title not availableJP2001305472A Title not availableJPH05130038A Title not availableWO2001031973A1Oct 28, 1999May 3, 2001Mitsubishi Denki Kabushiki KaishaSystem for reproducing three-dimensional sound field* Cited by examinerNon-Patent CitationsReference1Mita M. et al., "An Out-of-Plane Plolysilicon Actuator with a smooth vertical mirror or optical fiber switch application" Digest IEEE/LEOS Summer Topical Meetings, Jul. 1998, pp. 32-34, XP002936881.2Suga, T. et al. "A new wafer-bonder of ultra-high precision using surface activated bonding (SAB) concept" 2001 Proceedings 51<SUP>st</SUP>.Electronic Components and Technology Conference. ECTC 2001. Orlando, FL. May 29, 2001. Proceedings of the Electronic Components and Technology Conference, New York, NY, IEEE, US vol. Conf. 51, May 29, 2001, pp. 1013-1018, SPO10547715. ISBN: 0-7803-7038-4.Classifications U.S. Classification385/52, 385/14, 385/25International ClassificationG02B6/35, G02B6/26, H04Q11/00, H01L25/065Cooperative ClassificationH04Q11/0005, H04Q2011/0058, H04Q2011/0039, G02B6/3546, H04Q2011/003, G02B6/3596, G02B6/357, G02B6/3584, G02B6/3582, G02B6/3512European ClassificationH04Q11/00P2, G02B6/35WLegal EventsDateCodeEventDescriptionJun 24, 2004ASAssignmentOwner name: NIKON CORPORATION, JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AKAGAWA, KEIICHI;SUZUKI, YOSHIHIKO;ISHIZUYA, TOHRU;AND OTHERS;REEL/FRAME:015879/0141;SIGNING DATES FROM 20040512 TO 20040524Owner name: NTT ELECTRONICS CORPORATION, JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AKAGAWA, KEIICHI;SUZUKI, YOSHIHIKO;ISHIZUYA, TOHRU;AND OTHERS;REEL/FRAME:015879/0141;SIGNING DATES FROM 20040512 TO 20040524Oct 12, 2009REMIMaintenance fee reminder mailedMar 7, 2010LAPSLapse for failure to pay maintenance feesApr 27, 2010FPExpired due to failure to pay maintenance feeEffective date: 20100307RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services