This application relates generally to thermal actuators and more particularly to a thermal actuator that is suitable for use in an optical waveguide switch.
The traditional thermal actuator, the “V-beam” actuator, is widely used in microelectromechanical or “MEMS” structures. Such actuators are described in U.S. Pat. No. 5,909,078 to Robert L. Wood et al.; and in the U.S. Patents to Vijayakumar R. Dhuler et al., U.S. Pat. No. 5,994,816, No. 6,023,121, No. 6,114,794, No. 6,255,757 and No. 6,324,748; and in U.S. Pat. No. 6,360,539 to Edward A. Hill et al., all of the foregoing patents being incorporated by reference herein; and in the publication of Long Que, Jae-Sung Park and Yogesh B. Gianchandani, “Bent-Beam Electrothermal Actuators”; and in the publication of John M. Maloney, Don L. DeVoe and David S. Schreiber, “Analysis and Design of Electrothermal Actuators Fabricated from Single Crystal Silicon,” both of which publications are incorporated by reference herein.
However, these actuators are sensitive to residual stresses, especially the stress introduced by doping during fabrication of the actuator.
Indeed, the bent-beam geometry used in these actuators has been used in bent-beam strain sensors to measure residual stress as described in the publication of Yogesh B. Gianchandani and Khalil Najafi, “Bent-Beam Strain Sensors,” which publication is incorporated by reference herein.
The residual stress in the V-beam actuator acts to deflect the V-beams away from their originally-designed target locations since the beam angle gives rise to a transverse force. Moreover, when such a V-beam actuator is used in an optical waveguide switch, this residual stress results in waveguide misalignment. The amount of optical loss caused by this waveguide misalignment is substantial. As a result, currently the V-beam actuator is generally unacceptable for use in an optical waveguide switch.
Thus, there is a need for an actuator that is acceptable for use in an optical waveguide switch.
In a first aspect of the invention, a thermal actuator comprises a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a beam extending between the first support and the second support, the beam having a first side, a second side, a beam length and a beam mid-point, the beam being substantially straight along the first side; the beam comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment width orthogonal to the beam length, the beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to the beam vary along the beam length based on a predetermined pattern; so that a heating of the beam causes a beam buckling and the beam mid-point to translate in a predetermined direction generally normal to and outward from the second side.
In a second aspect of the invention, a thermal actuator comprises a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a plurality of beams extending in parallel between the first support and the second support, thus forming a beam array; each beam of the beam array having a first side, a second side, a beam length and a beam mid-point, each beam being substantially straight along its first side; each beam of the beam array comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment width orthogonal to the beam length, each beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to each beam vary along the beam length based on a predetermined pattern; an included coupling beam extending orthogonally across the beam array to couple each beam of the beam array substantially at the corresponding beam mid-point; so that a heating of the beam array causes a beam array buckling and the coupling beam to translate in a predetermined direction generally normal to and outward from the second sides of the array beams.
In a third aspect of the invention, a thermal actuator comprises a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a beam extending between the first support and the second support, the beam having a first side, a second side, a beam length and a beam mid-point, the beam being substantially straight along the second side; the beam comprised of a plurality of beam segments, each beam segment of the plurality of beam segments being having a beam segment width orthogonal to the beam length, the beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to the beam vary along the beam length based on a predetermined pattern; so that a heating of the beam causes a beam buckling and the beam mid-point to translate in a predetermined direction generally normal to and outward from the second side.
In a fourth aspect of the invention, a thermal actuator comprises a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a plurality of beams extending in parallel between the first support and the second support, thus forming a beam array; each beam of the beam array having a first side, a second side, a beam length and a beam mid-point, each beam being substantially straight along its second side; each beam of the beam array comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment width orthogonal to the beam length, each beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to each beam vary along the beam length based on a predetermined pattern; an included coupling beam extending orthogonally across the beam array to couple each beam of the beam array substantially at the corresponding beam mid-point; so that a heating of the beam array causes a beam array buckling and the coupling beam to translate in a predetermined direction generally normal to and outward from the second sides of the array beams.
In a fifth aspect of the invention, a thermal actuator comprises a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a beam extending between the first support and the second support, the beam having a first side, a second side, a beam length and a beam mid-point, the beam being substantially straight along the first side; the beam comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment average width orthogonal to the beam length, the beam thus forming a corresponding plurality of beam segment average widths; wherein the plurality of beam segment average widths corresponding to the beam vary along the beam length based on a predetermined pattern; so that a heating of the beam causes a beam buckling and the beam mid-point to translate in a predetermined direction generally normal to and outward from the second side.
In a sixth aspect of the invention, a thermal actuator comprises a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a plurality of beams extending in parallel between the first support and the second support, thus forming a beam array; each beam of the beam array having a first side, a second side, a beam length and a beam mid-point, each beam being substantially straight along its first side; each beam of the beam array comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment average width orthogonal to the beam length, each beam thus forming a corresponding plurality of beam segment average widths; wherein the plurality of beam segment average widths corresponding to each beam vary along the beam length based on a predetermined pattern; an included coupling beam extending orthogonally across the beam array to couple each beam of the beam array substantially at the corresponding beam mid-point; so that a heating of the beam array causes a beam array buckling and the coupling beam to translate in a predetermined direction generally normal to and outward from the second sides of the array beams.
In a seventh aspect of the invention, an optical waveguide switch comprises a thermal actuator, the thermal actuator comprising a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a beam extending between the first support and the second support, the beam having a first side, a second side, a beam length and a beam mid-point, the beam being substantially straight along the first side; the beam comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment width orthogonal to the beam length, the beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to the beam vary along the beam length based on a predetermined pattern; so that a heating of the beam causes a beam buckling and the beam mid-point to translate in a predetermined direction generally normal to and outward from the second side.
In an eighth aspect of the invention, an optical waveguide switch comprises a thermal actuator, the thermal actuator comprising a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a plurality of beams extending in parallel between the first support and the second support, thus forming a beam array; each beam of the beam array having a first side, a second side, a beam length and a beam mid-point, each beam being substantially straight along its first side; each beam of the beam array comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment width orthogonal to the beam length, each beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to each beam vary along the beam length based on a predetermined pattern; an included coupling beam extending orthogonally across the beam array to couple each beam of the beam array substantially at the corresponding beam mid-point; so that a heating of the beam array causes a beam array buckling and the coupling beam to translate in a predetermined direction generally normal to and outward from the second sides of the array beams.
In a ninth aspect of the invention, an optical waveguide switch comprises a thermal actuator, the thermal actuator comprising a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a beam extending between the first support and the second support, the beam having a first side, a second side, a beam length and a beam mid-point, the beam being substantially straight along the second side; the beam comprised of a plurality of beam segments, each beam segment of the plurality of beam segments being having a beam segment width orthogonal to the beam length, the beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to the beam vary along the beam length based on a predetermined pattern; so that a heating of the beam causes a beam buckling and the beam mid-point to translate in a predetermined direction generally normal to and outward from the second side.
In a tenth aspect of the invention, an optical waveguide switch comprises a thermal actuator, the thermal actuator comprising a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a plurality of beams extending in parallel between the first support and the second support, thus forming a beam array; each beam of the beam array having a first side, a second side, a beam length and a beam mid-point, each beam being substantially straight along its second side; each beam of the beam array comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment width orthogonal to the beam length, each beam thus forming a corresponding plurality of beam segment widths; wherein the plurality of beam segment widths corresponding to each beam vary along the beam length based on a predetermined pattern; an included coupling beam extending orthogonally across the beam array to couple each beam of the beam array substantially at the corresponding beam mid-point; so that a heating of the beam array causes a beam array buckling and the coupling beam to translate in a predetermined direction generally normal to and outward from the second sides of the array beams.
In an eleventh aspect of the invention, an optical waveguide switch comprises a thermal actuator, the thermal actuator comprising a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a beam extending between the first support and the second support, the beam having a first side, a second side, a beam length and a beam mid-point, the beam being substantially straight along the first side; the beam comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment average width orthogonal to the beam length, the beam thus forming a corresponding plurality of beam segment average widths; wherein the plurality of beam segment average widths corresponding to the beam vary along the beam length based on a predetermined pattern; so that a heating of the beam causes a beam buckling and the beam mid-point to translate in a predetermined direction generally normal to and outward from the second side.
In a twelfth aspect of the invention, an optical waveguide switch comprises a thermal actuator, the thermal actuator comprising a substrate having a surface; a first support and a second support disposed on the surface and extending orthogonally therefrom; a plurality of beams extending in parallel between the first support and the second support, thus forming a beam array; each beam of the beam array having a first side, a second side, a beam length and a beam mid-point, each beam being substantially straight along its first side; each beam of the beam array comprised of a plurality of beam segments, each beam segment of the plurality of beam segments having a beam segment average width orthogonal to the beam length, each beam thus forming a corresponding plurality of beam segment average widths; wherein the plurality of beam segment average widths corresponding to each beam vary along the beam length based on a predetermined pattern; an included coupling beam extending orthogonally across the beam array to couple each beam of the beam array substantially at the corresponding beam mid-point; so that a heating of the beam array causes a beam array buckling and the coupling beam to translate in a predetermined direction generally normal to and outward from the second sides of the array beams.
Referring now to the optical waveguide switches 100a, 100b, 100c and their corresponding thermal actuators 200, 300, 400 described below in connection with
Referring now to the optical waveguide switches 100d and 100f and their corresponding thermal actuators 500 and 700 described below in connection with
Referring now to the optical waveguide switches 100e and 100g and their corresponding thermal actuators 600 and 800 described below in connection with
Referring now to the optical waveguide switch 100h and its corresponding thermal actuator 900 described below in connection with FIGS. 17 and 43–48, in brief, a thermal actuator 900 comprises a substantially straight beam 910. The beam has a beam length 918 and a beam mid-point 919. The beam comprises a plurality of beam segments 920, 921, 922, 923, 924 with beam segment lengths. Each beam segment has a beam segment average width, thus forming a corresponding plurality of beam segment average widths 925, 931, 926, 933, 927. The beam segment average widths vary along the beam length based on a predetermined pattern. As the beam is heated by an included heating means, the beam buckles. The buckling of the beam, in turn, causes the beam mid-point to translate or move in a predetermined direction 948. The beam mid-point movement, in turn, operates an included optical waveguide switch 100h. The heating means comprises any of Joule heating, eddy current heating, conduction heating, convection heating and radiation heating.
Referring now to the optical waveguide switch 100i and its corresponding thermal actuator 1000 described below in connection with FIGS. 18 and 49–54, in brief, a thermal actuator 1000 comprises a plurality of beams 1010a, 1010b, 1010c, the plurality of beams arranged to form a beam array 1009. Each beam comprises a plurality of beam segments 1020, 1021, 1022, 1023, 1024. Each beam segment has a beam segment average width, the plurality of beams thus forming a corresponding plurality of beam segment average widths 1025a, 1031a, 1026a, 1033a, 1027a; 1025b, 1031b, 1026b, 1033b, 1027b; 1025c, 1031c, 1026c, 1033c, 1027c. The plurality of beam segment average widths corresponding to each beam vary along the beam length based on a predetermined pattern. The mid-point 1019 of each beam is attached or coupled to an orthogonal coupling beam 1005. As the plurality of beams are heated by an included heating means, the beam array buckles. The buckling of the beams in the beam array, in turn, causes the attached coupling beam to more in a predetermined direction 1048. The coupling beam movement, in turn, operates an included optical waveguide switch 100i. The heating means comprises any of Joule heating, eddy current heating, conduction heating, convection heating and radiation heating.
Referring now to
Referring now to
Referring now to
Examples of optical waveguide switches that incorporate thermal actuators have been described in the application of Joel Kubby, U.S. Pat. Application No. 60/456,086, filed Mar. 19, 2003; and in the applications of Joel Kubby et al., U.S. patent application Ser. No. 09/986,395, filed Nov. 8, 2001, now U.S. patent application Publication No. 20030086641, published May 8, 2003; and U.S. Pat. Application No. 60/456,063, filed Mar. 19, 2003, all of the foregoing patent applications being incorporated by reference herein.
Referring now to
The predetermined pattern is characterized in that, across the beam array 214 from one side 250 of the beam array to the opposite side 252 of the beam array, successive beam width values do not decrease and at least sometimes increase.
Each pair 222 of adjacent beams in the beam array 214 has a beam spacing 224 with a corresponding beam spacing value, with all such pairs of adjacent beams in the beam array having substantially the same beam spacing value.
As shown in
The heater layer 228 can be thermally isolated from the substrate as described in U.S. Pat. No. 5,706,041 and No. 5,851,412 to Joel Kubby, both of which patents are incorporated by reference herein.
Further, in one embodiment, each beam of the plurality of beams is arranged to be heated by a beam heater current 246 supplied by an included beam input 242 and beam output 244, thus resulting in a heating of the plurality of beams.
The plurality of beams can be thermally isolated from the substrate as described in the application of Joel Kubby, U.S. patent application Ser. No. 09/683,533, filed Jan. 16, 2002, now U.S. Patent Application Publication No. 20030134445, published Jul. 17, 2003, which patent application is incorporated by reference herein.
As shown, the plurality of beams is arranged so that the heating of the plurality of beams causes a beam buckling and the coupling beam to translate in a predetermined direction 248. In one embodiment, the heating of the plurality of beams is supplied by the heater layer 228. In another embodiment, the heating of the plurality of beams is supplied by the beam heater current 246. In still another embodiment, the heating of the plurality of beams is supplied by a combination of the heater layer 228 and the beam heater current 246.
Referring generally to
In one embodiment, each beam of the plurality of beams is fabricated in a device layer 230 of a silicon-on-insulator wafer 232.
A method for fabricating the plurality of beams in a device layer of a silicon-on-insulator wafer is described in the U.S. Patents to Phillip D. Floyd et al., U.S. Pat. No. 6,002,507 and No. 6,014,240; and in the U.S. Patents to Joel Kubby et al., U.S. Pat. No. 6,362,512 and No. 6,379,989, all of the foregoing patents being incorporated by reference herein.
In one embodiment, the first support 206 and second support 208 are fabricated in a buried oxide layer 234 of a silicon-on-insulator wafer 232.
Referring now to
The predetermined pattern is characterized in that, across the beam array 314 from one side 350 of the beam array to the opposite side 352 of the beam array, successive beam spacing values do not decrease and at least sometimes increase.
Each beam of the beam array 314 has a beam width 326 with a corresponding beam width value, with all beams of the beam array having substantially the same beam width value.
As shown in
Further, in one embodiment, each beam of the plurality of beams is arranged to be heated by a beam heater current 346 supplied by an included beam input 342 and beam output 344, thus resulting in a heating of the plurality of beams.
As shown, the plurality of beams is arranged so that the heating of the plurality of beams causes a beam buckling and the coupling beam to translate in a predetermined direction 348. In one embodiment, the heating of the plurality of beams is supplied by the heater layer 328. In another embodiment, the heating of the plurality of beams is supplied by the beam heater current 346. In still another embodiment, the heating of the plurality of beams is supplied by a combination of the heater layer 328 and the beam heater current 346.
Referring generally to
In one embodiment, each beam of the plurality of beams is fabricated in a device layer 330 of a silicon-on-insulator wafer 332.
In one embodiment, the first support 306 and the second support 308 are fabricated in a buried oxide layer 334 of a silicon-on-insulator wafer 332.
Referring now to
The predetermined pattern is characterized in that, across the beam array 414 from one side 450 of the beam array to the opposite side 452 of the beam array, successive beam resistance values do not increase and at least sometimes decrease.
Each beam of the beam array 414 has a beam width 426 with a corresponding beam width value, with all beams of the beam array having substantially the same beam width value.
Each pair 422 of adjacent beams in the beam array 414 defines a beam spacing 424 with a corresponding beam spacing value, with all such pairs of adjacent beams in the beam array having substantially the same beam spacing value.
As shown in
As shown, the plurality of beams is arranged so that the heating of the plurality of beams causes a beam buckling and the coupling beam to translate in a predetermined direction 448.
Referring generally to
In one embodiment, each beam of the plurality of beams is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In one embodiment, each beam of the plurality of beams is fabricated in a device layer 430 of a silicon-on-insulator wafer 432.
In one embodiment, the first support 406 and the second support 408 are fabricated in a buried oxide layer 434 of a silicon-on-insulator wafer 432.
Referring again to
In
An example of a beam heating parameter 254 is the beam width 226. The beam width w will effect the heat flow ∂Q/∂t through the beam under a temperature gradient ∂T/∂x as determined by Fourier's law of heat conduction in one dimension;
∂Q/∂t=λ(T)A∂T/∂x;
where the beam cross-section area A is given by the product of the beam width w and the beam thickness t;
A=(w)(t);
and λ(T) is the temperature-dependent thermal conductivity of the beam. The beam width w will also effect the heat capacity of the beam, and thus the temperature of the beam as a function of time for a given heat input Q as given in one dimension by the heat equation;
ρC∂T/∂t−λ(T)∂T2/∂x2=Q+h(text−T)
where ρ is the density of the beam, C is the heat capacity of the beam, h is the convective heat transfer coefficient, and Text is the external temperature. For a given beam thickness t, a wider beam width w will increase the heat capacity of the beam, and thus decrease the temperature the beam will reach after a certain amount of time for a given heat input Q.
A further example of a beam heating parameter 254 is the beam spacing 224. Heat can be transferred between beams by conduction, convection and radiation. The smaller the beam spacing, the greater the heat transfer between beams. Heat lost by one beam can be transferred to a nearby beam, and vice-versa. Heat can also be lost from beams by conduction, convection and radiation to the surrounding environment. The larger the beam spacing, the greater the heat loss from a beam to the surrounding environment.
A final example of a beam heating parameter 254 is the beam electrical resistance R. The beam resistance R will effect the amount of heat Q generated by a current I flowing through a beam with a resistance R for a time t by;
Q=I2Rt
as given by Joule's law.
Each beam of the beam array 214 is characterized by an average beam temperature 236a–236d, the average beam temperatures of the array beams thus forming an average beam temperature distribution 256. Further, there is provided heating means to heat each beam of the plurality of beams, thus causing or forming a heating of the plurality of beams. The heating means includes any of direct current Joule heating, by passing a beam heater current such as, for example, the beam current 246 through each beam, and indirect heating by conduction, convection or radiation from a heater layer such as, for example, the heater layer 228 disposed on the substrate, by passing a heater current through the heater layer. Further, in embodiments using a heater layer, the heater layer can be thermally isolated from the substrate as described in U.S. Pat. No. 5,706,041 and No. 5,851,412 to Joel Kubby, and in U.S. Pat. No. 6,362,512 to Joel Kubby et al., all of which patents are incorporated by reference herein.
The predetermined pattern is characterized in that, across the beam array 214 from one side 250 of the beam array to the opposite side 252 of the beam array, successive beam heating parameter values are arranged so that the beam temperature distribution becomes asymmetric based on the heating of the plurality of beams.
As shown, the plurality of beams is arranged so that the heating of the plurality of beams causes a beam buckling and the coupling beam 220 to translate in a predetermined direction 248.
Further heating of the plurality of the beams causes further expansion of the beams, thus causing the coupling beam to further translate in the predetermined direction 248.
In one embodiment, the heating of the plurality of beams comprises any of Joule heating, eddy current heating, conduction heating, convection heating and radiation heating.
Referring again to
In
Each beam of the beam array 314 is characterized by an average beam temperature, the average beam temperatures of the array beams thus forming an average beam temperature distribution. Further, there is provided heating means to heat each beam of the plurality of beams, thus causing or forming a heating of the plurality of beams. The heating means includes any of direct current Joule heating, by passing a beam heater current such as, for example, the beam current 346 through each beam, and indirect heating by conduction, convection or radiation from a heater layer such as, for example, the heater layer 328 disposed on the substrate, by passing a heater current through the heater layer. Further, in embodiments using a heater layer, the heater layer can be thermally isolated from the substrate as described in U.S. Pat. Nos. 5,706,041 and No. 5,851,412 to Joel Kubby, and in U.S. Pat. No. 6,362,512 to Joel Kubby et al., all of which patents are incorporated by reference herein.
The predetermined pattern is characterized in that, across the beam array 314 from one side 350 of the beam array to the opposite side 352 of the beam array, successive beam heating parameter values are arranged so that the beam temperature distribution becomes asymmetric based on the heating of the plurality of beams.
As shown, the plurality of beams is arranged so that the heating of the plurality of beams causes a beam buckling and the coupling beam 320 to translate in a predetermined direction 348.
In one embodiment, the heating of the plurality of beams comprises any of Joule heating, eddy current heating, conduction heating, convection heating and radiation heating.
Referring again to
In
Each beam of the beam array 414 is characterized by an average beam temperature, the average beam temperatures of the array beams thus forming an average beam temperature distribution. Further, there is provided heating means to heat each beam of the plurality of beams, thus causing or forming a heating of the plurality of beams. The heating means includes any of direct current Joule heating, by passing a beam heater current such as, for example, the beam current 446 through each beam, and indirect heating by conduction, convection or radiation from a heater layer such as, for example, the heater layer 428 disposed on the substrate, by passing a heater current through the heater layer. Further, in embodiments using a heater layer, the heater layer can be thermally isolated from the substrate as described in U.S. Pat. Nos. 5,706,041 and No. 5,851,412 to Joel Kubby, and in U.S. Pat. No. 6,362,512 to Joel Kubby et al., all of which patents are incorporated by reference herein.
The predetermined pattern is characterized in that, across the beam array 414 from one side 450 of the beam array to the opposite side 452 of the beam array, successive beam heating parameter values are arranged so that the beam temperature distribution becomes asymmetric based on the heating of the plurality of beams.
As shown, the plurality of beams is arranged so that the heating of the plurality of beams causes a beam buckling and the coupling beam 420 to translate in a predetermined direction 448.
In one embodiment, the heating of the plurality of beams comprises any of Joule heating, eddy current heating, conduction heating, convection heating and radiation heating.
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
As shown in
As shown in
In one embodiment, the heating of the beam 510 is provided by an included heater layer 528 disposed on the surface 504, the heater layer coupled to a heater layer input 538 and a heater layer output 540.
In another embodiment, the heating of the beam 510 is provided by a beam heater current 546 supplied by an included beam input 542 and beam output 544.
In one embodiment, the beam is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In another embodiment, the beam is fabricated in a device layer of a silicon-on-insulator wafer.
As shown in
In another embodiment, the beam 510 comprises a plurality (n) of beam segments, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
As shown in
As further shown in
Referring now to
As shown in
In one embodiment, the predetermined pattern is characterized in that, along the beam length 618 from the first support 606 to the beam mid-point 619, beam segment widths 625a, 626a, 627a; 625b, 626b, 627b corresponding to successive beam segments 620, 622 do not decrease and at least sometimes increase, and along the beam length 618 from the beam mid-point 619 to the second support 608, beam segment widths 625b, 626b, 627b; 625c, 626c, 627c corresponding to successive beam segments 622, 624 do not increase and at least sometimes decrease.
In one embodiment, the heating of the beam array is provided by an included heater layer 628 disposed on the surface 604, the heater layer coupled to a heater layer input 638 and a heater layer output 640.
In another embodiment, each beam of the beam array is heated by a beam heater current 646a, 646b, 646c supplied by an included beam input 642 and beam output 644, thus forming the heating of the beam array.
In one embodiment, each beam of the beam array is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In another embodiment, each beam of the beam array is fabricated in a device layer of a silicon-on-insulator wafer.
As shown in
In another embodiment, each beam of the beam array 613 comprises a plurality (n) of beam segments, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
As shown in
In another embodiment, the beam array 613 comprises a plurality (n) of beams, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
Referring now to
As shown in
As shown in
In one embodiment, the heating of the beam 710 is provided by an included heater layer 728 disposed on the surface 704, the heater layer coupled to a heater layer input 738 and a heater layer output 740.
In another embodiment, the heating of the beam 710 is provided by a beam heater current 746 supplied by an included beam input 742 and beam output 744.
In one embodiment, the beam is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In another embodiment, the beam is fabricated in a device layer of a silicon-on-insulator wafer.
As shown in
In another embodiment, the beam 710 comprises a plurality (n) of beam segments, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
As shown, in one embodiment, the beam 710 comprises exclusively beam segments 720, 722, 724 having substantially parallel sides.
As shown, in one embodiment, the beam 710 comprises exactly two (2) beam segments 720, 724 that are substantially equal with respect to their corresponding beam segment lengths and beam segment widths 725, 727.
Referring now to
As shown in
As shown in
In one embodiment, the heating of the beam array is provided by an included heater layer 828 disposed on the surface 804, the heater layer coupled to a heater layer input 838 and a heater layer output 840.
In another embodiment, each beam of the beam array is heated by a beam heater current 846a, 846b, 846c supplied by an included beam input 842 and beam output 844, thus forming the heating of the beam array.
In one embodiment, each beam of the beam array is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In another embodiment, each beam of the beam array is fabricated in a device layer of a silicon-on-insulator wafer.
As shown in
In another embodiment, each beam of the beam array 813 comprises a plurality (n) of beam segments, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
As shown in
In another embodiment, the beam array 813 comprises a plurality (n) of beams, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
Referring now to
As shown in
As shown in
Still referring to
In one embodiment, the heating of the beam 910 is provided by an included heater layer 928 disposed on the surface 904, the heater layer coupled to a heater layer input 938 and a heater layer output 940.
In another embodiment, the heating of the beam 910 is provided by a beam heater current 946 supplied by an included beam input 942 and beam output 944.
In one embodiment, the beam is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In another embodiment, the beam is fabricated in a device layer of a silicon-on-insulator wafer.
As shown in
In another embodiment, the beam 910 comprises a plurality (n) of beam segments, where n does not equal 5. In this embodiment, for example, n equals 2, 3, 4, 6, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
As shown, in one embodiment, the beam 910 comprises exactly three (3) beam segments 920, 922, 924 having substantially parallel sides.
As shown, in one embodiment, the beam 910 comprises exactly two (2) beam segments 920, 924 that are substantially equal with respect to their corresponding beam segment lengths and beam segment widths 925, 927.
Referring now to
As shown in
As shown in
Still referring to
In one embodiment, the heating of the beam array 1009 is provided by an included heater layer 1028 disposed on the surface 1004, the heater layer coupled to a heater layer input 1038 and a heater layer output 1040.
In another embodiment, each beam of the beam array 1009 is heated by a beam heater current 1046a, 1046b, 1046c supplied by an included beam input 1042 and beam output 1044, thus forming the heating of the beam array.
In one embodiment, each beam of the beam array is fabricated of a low-conductivity material of either monocrystalline silicon or polycrystalline silicon.
In another embodiment, each beam of the beam array is fabricated in a device layer of a silicon-on-insulator wafer.
As shown in
In another embodiment, each beam of the beam array 1009 comprises a plurality (n) of beam segments, where n does not equal 5. In this embodiment, for example, n equals 2, 3, 4, 6, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
As shown in
In another embodiment, the beam array 1009 comprises a plurality (n) of beams, where n does not equal 3. In this embodiment, for example, n equals 2, 4, 5, 12, 15, 32, 82, 109, 188, 519, 1003, etc.
The table below lists the drawing element reference numbers together with their corresponding written description:
While various embodiments of a thermal actuator and an optical waveguide switch including the same, in accordance with the present invention, have been described hereinabove, the scope of the invention is defined by the following claims.
This is a continuation-in-part of its commonly-assigned “parent” prior application Ser. No. 10/634,941, filed 5 Aug. 2003, now pending, by Joel A. Kubby et al., the same inventors as in the present application, entitled “A thermal actuator and an optical waveguide switch including the same”, the disclosure of which prior application is hereby incorporated by reference verbatim, with the same effect as though such disclosure were fully and completely set forth herein. This application is related to the commonly-assigned application Ser. No. 10/772,693, filed on the same date as the present application, now pending, by Joel A. Kubby et al., the same inventors as in the present application, entitled “A thermal actuator with offset beam segment neutral axes and an optical waveguide switch including the same”. The disclosures of the, following thirteen (13) U.S. patents are hereby incorporated by reference, verbatim, and with the same effect as though the same disclosures were fully and completely set forth herein: Joel Kubby, U.S. Pat. No. 5,706,041, “Thermal ink-jet printhead with a suspended heating element in each ejector,” issued Jan. 6, 1998; Joel Kubby, U.S. Pat. No. 5,851,412, “Thermal ink-jet printhead with a suspended heating element in each ejector,” issued Dec. 22, 1998; Joel Kubby et al., U.S. Pat. No. 6,362,512, “Microelectromechanical structures defined from silicon on insulator wafers,” issued Mar. 26, 2002; Joel Kubby et al., U.S. Pat. No. 6,379,989, “Process for manufacture of microoptomechanical structures,” issued Apr. 30, 2002; Phillip D. Floyd et al., U.S. Pat. No. 6,002,507, “Method and apparatus for an integrated laser beam scanner,” issued Dec. 14, 1999; Phillip D. Floyd et al., U.S. Pat. No. 6,014,240, “Method and apparatus for an integrated laser beam scanner using a carrier substrate,” issued Jan. 11, 2000; Robert L. Wood et al., U.S. Pat. No. 5,909,078, “Thermal arched beam microelectromechanical actuators,” issued Jun. 1, 1999; Vijayakumar R. Dhuler et al., U.S. Pat. No. 5,994,816, “Thermal arched beam microelectromechanical devices and associated fabrication methods,” issued Nov. 30, 1999; Vijayakumar R. Dhuler et al., U.S. Pat. No. 6,023,121, “Thermal arched beam microelectromechanical structure,” issued Feb. 8, 2000; Vijayakumar R. Dhuler et al., U.S. Pat. No. 6,114,794, “Thermal arched beam microelectromechanical valve,” issued Sep. 5, 2000; Vijayakumar R. Dhuler et al., U.S. Pat. No. 6,255,757, “Microactuators including a metal layer on distal portions of an arched beam,” issued Jul. 3, 2001; Vijayakumar R. Dhuler et al., U.S. Pat. No. 6,324,748, “Method of fabricating a microelectro mechanical structure having an arched beam,” issued Dec. 4, 2001; and Edward A. Hill et al., U.S. Pat. No. 6,360,539, “Microelectromechanical actuators including driven arched beams for mechanical advantage,” issued Mar. 26, 2002. The disclosures of the following four (4) U.S. patent applications are hereby incorporated by reference, verbatim, and with the same effect as though the same disclosures were fully and completely set forth herein: Joel Kubby, U.S. patent application Ser. No. 09/683,533, “Systems and methods for thermal isolation of a silicon structure,” filed Jan. 16, 2002, now U.S. Patent Application Publication No. 20030134445, published Jul. 17, 2003; Joel Kubby, U.S. Pat. Application No. 60/456,086, “MxN Cantilever Beam Optical-Waveguide Switch,” filed Mar. 19, 2003; Joel Kubby et al., U.S. patent application Ser. No. 09/986,395, “Monolithic reconfigurable optical multiplexer systems and methods,” filed Nov. 8, 2001, now U.S. Patent Application Publication No. 20030086641, published May 8, 2003; and Joel Kubby et al., U.S. Pat. Application No. 60/456,063, “MEMS Optical Latching Switch,” filed Mar. 19, 2003. The disclosures of the following three (3) publications are hereby incorporated by reference, verbatim, and with the same effect as though the same disclosures were fully and completely set forth herein: Yogesh B. Gianchandani and Khalil Najafi, “Bent-Beam Strain Sensors,” Journal of Microelectromechanical Systems, Vol. 5, No.1, March 1996, pages 52–58; Long Que, Jae-Sung Park and Yogesh B. Gianchandani, “Bent-Beam Electrothermal Actuators,” Journal of Microelectromechanical Systems, Vol. 10, No. 2, June 2001, pages 247–254; and John M. Maloney, Don L. DeVoe and David S. Schreiber, “Analysis and Design of Electrothermal Actuators Fabricated from Single Crystal Silicon,” Proceedings ASME International Mechanical Engineering Conference and Exposition, Orlando, Fla., pages 233–240, 2000.
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Child | 10772564 | US |