Adiabatic optical interface fixed using photoactivation lithography

Abstract

A system and method for aligning optical elements to form an adiabatic coupling are disclosed. The alignment device includes a common platform and a plurality of electrically controlled mounts attached to the common platform. Each fiber of the first set of fibers to be aligned with a second set of fibers is coupled to a corresponding of the plurality of electrically controlled mounts. The entire platform is positioned in 3D space to align the first set of fibers with the second set of fibers to a degree of alignment within a predetermined threshold level. Each electrically controlled mount is then adjusted so that each fiber of the first set of fibers is further aligned with the corresponding fiber of the second set of fibers. In some embodiments, scattered light and / or signal intensity are used as feedback measurements to guide the alignment process.

Description

Background Art

[0001] Quantum computing uses the laws of quantum physics to process information. Quantum physics is a theory that describes the behavior of reality at a fundamental level. Currently, quantum physics is the only physical theory capable of consistently predicting the behavior of microscopic quantum objects (such as particles), such as photons, molecules, atoms, and electrons.

[0002] A quantum computing device is a device that uses quantum mechanics to enable the writing, storage, processing, and reading of information encoded in a quantum state, such as the state of a quantum object. A quantum object is a physical object that behaves according to the laws of quantum physics. The state of a physical object is a description of the object at a given time.

[0003] In quantum mechanics, the state of a two-level quantum system, or simply what is called a qubit, is a list consisting of two complex numbers, and the sum of the squares of the absolute values of the complex numbers (e.g., |x| 2 +|y| 2 ) must be equal to 1. The two complex numbers (e.g., x and y) are each called an amplitude, and the respective probabilities are the squares of the absolute values of the complex numbers (e.g., |x| 2 and |y| 2 ). Therefore, the square of the absolute value of each complex number corresponds to the probability that event 0 or event 1 occurs, respectively. The fundamental and counterintuitive difference between a probabilistic bit (such as a conventional 0 or ¹ bit) and a qubit is that a probabilistic bit represents a lack of information about a two-level classical system, while a qubit contains the maximum amount of information about a two-level quantum system.

[0004] Quantum computers are based on such qubits, which can experience phenomena called "superposition" and "entanglement." Superposition allows a quantum system to be in multiple states simultaneously. For example, while classical computers are based on bits that are either 0 or 1, qubits can be both 0 and 1 at the same time, with different probabilities assigned to 0 and 1. Entanglement is a strong correlation between quantum particles, resulting in them being bound together as a single unit, even when separated by large distances.

[0005] There are different types of qubits that can be used in quantum computers, each with different advantages and disadvantages. For example, a quantum computer may include qubits composed of superconductors, trapped ions, semiconductors, photons, etc. Each may have different levels of interference, error, and decoherence. Also, some may be more useful for generating certain types of quantum circuits or quantum algorithms, while others may be more useful for generating other types of quantum circuits or quantum algorithms. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a block diagram showing a process for fixing aligned tapered ends of optical elements forming an adiabatic bond according to several embodiments, the process comprising fixing at least one of the optical elements to an optical device structure with an adhesive, and forming an additional fixing structure on the aligned tapered ends using a photoactive material and photolithography.

[0007] [Figure 2] Figure 2 is a flowchart illustrating the steps of a process for fixing the aligned tapered end of an optical element using a fixed structure formed using a photoactive material and photolithography, according to several embodiments.

[0008] [Figure 3] Figure 3 is a block diagram showing that, in several embodiments, photoactivation lithography is performed to form a fixed structure on the aligned tapered end of an adiabatic-coupled optical element.

[0009] [Figure 4] Figure 4 is a perspective view of an example of a fixing structure for fixing an adiabatic-coupled optical element formed using a photoactive material and photolithography, according to several embodiments.

[0010] [Figure 5] Figure 5 shows a side view of one example of a fixed structure having a cylindrical outer shape according to several embodiments.

[0011] [Figure 6] Figure 6 shows a side view of one example of a fixed structure having an inverted hourglass shape according to several embodiments.

[0012] [Figure 7] Figure 7 shows a plan view of an optical device in which one set of optical elements is adiabatically coupled to another set of optical elements, according to several embodiments, and a fixed structure formed by photoactivation lithography fixes the adiabatically coupled set of optical elements.

[0013] [Figure 8] Figure 8 shows an example implementation of an optical device capable of transmitting light through adiabatic-coupled optical elements fixed using a fixed structure formed using photoactivation lithography, according to several embodiments.

[0014] [Figure 9] Figures 9A-9B show examples of implementations of optical devices, such as quantum memory devices (e.g., quantum repeaters), that can transmit light through adiabatic-coupled optical elements fixed using a fixed structure formed using photoactivation lithography, according to several embodiments.

[0015] [Figure 10] FIG. 10 shows an example of a quantum memory device according to some embodiments, and the quantum information storage device of the quantum memory device can supply photons through an adiabatically coupled optical element fixed using a fixed structure formed using photoactivated lithography.

[0016] [Figure 11] FIGS. 11A-11B show how an optical device, such as a quantum memory device, including an adiabatically coupled optical element fixed using a fixed structure formed using photoactivated lithography, is installed in a cryogenic cooling device according to some embodiments.

[0017] [Figure 12] FIG. 12 is an illustrative diagram showing how entanglement is extended by performing a joint measurement of received particles of each set of entangled particles distributed via an optical fiber network link to and / or from, for example, a quantum memory device according to some embodiments.

[0018] [Figure 13] FIG. 13 shows an implementation of an example of an optical device in a satellite communication system or the like according to some embodiments, and the optical device may include an adiabatically coupled optical element fixed using a fixed structure formed using photoactivated lithography.

[0019] [Figure 14A] FIG. 14A shows a perspective view of a block diagram of an optical element alignment device including a movable platform and individual electrically controllable optical element mounts included on the movable platform according to some embodiments.

[0020] [Figure 14B]FIG. 14B shows a top view of a block diagram of an optical element alignment apparatus including a movable platform and individual electrically controllable optical element mounts included on the movable platform, according to some embodiments.

[0021] [Figure 15] FIG. 15 is a flowchart showing steps of a process of aligning tapered ends of a first set of optical elements with tapered ends of a second set of optical elements using an optical element alignment apparatus including a movable platform and individual electrically controllable optical element mounts included on the movable platform, according to some embodiments.

[0022] [Figure 16] FIGS. 16A-16B show that the movable platform of the optical element alignment apparatus is adjusted in a vertical direction to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements, according to some embodiments.

[0023] [Figure 17] FIGS. 17A-17B show that the movable platform of the optical element alignment apparatus is adjusted in a horizontal direction to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements, according to some embodiments.

[0024] [Figure 18] FIGS. 18A-18B show that the movable platform of the optical element alignment apparatus is adjusted in a depth direction to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements, according to some embodiments.

[0025] [Figure 19]Figures 19A-19B show that, in several embodiments, the movable platform of an optical element alignment device is rotated to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements.

[0026] [Figure 20] Figure 20 is a block diagram showing components of an electrically controllable optical element mount, including a piezoelectric material configured to individually adjust the position of a single optical element in at least two directions, according to several embodiments.

[0027] [Figure 21] Figure 21 is a block diagram showing a cross-sectional view of a movable platform of an optical element alignment device, in which multiple electrically controllable optical element mounts are mounted on the movable platform, according to several embodiments.

[0028] [Figure 22] Figure 22 shows that, according to several embodiments, a first set of distinct movements distinct from each other are applied at a first time point via different electrically controllable optical element mounts mounted on a movable platform.

[0029] [Figure 23] Figure 23 shows that, according to several embodiments, a different set of distinct movements is applied at subsequent time points via different electrically controllable optical element mounts mounted on a movable platform.

[0030] [Figure 24] Figure 24 is a flowchart showing the first step of a process in which the tapered ends of a first set of optical elements are aligned with the tapered ends of a second set of optical elements using an optical element alignment device, according to several embodiments.

[0031] [Figure 25]Figure 25 is a flowchart showing the second step of a process in which the tapered ends of a first set of optical elements are aligned with the tapered ends of a second set of optical elements using an optical element alignment device, according to several embodiments.

[0032] [Figure 26] Figure 26 is a flowchart showing the third step of a process in which the tapered ends of a first set of optical elements are aligned with the tapered ends of a second set of optical elements using an optical element alignment device, according to several embodiments.

[0033] [Figure 27] Figure 27 is a block diagram showing an example of a computing device that may be used in at least some embodiments. [Overview of the project]

[0034] Here, embodiments are described by example with respect to several embodiments and explanatory drawings, but those skilled in the art will recognize that embodiments are not limited to the embodiments or drawings described herein. It should be understood that the drawings and the detailed descriptions relating thereto are not intended to limit embodiments to any particular form disclosed, but rather to encompass all modifications, equivalents, and substitutes that fall within the spirit and scope defined by the appended claims. Headings used herein are for organizational purposes only and are not intended to limit the scope of the description or claims. Throughout this application, the word “may” is used in an allowable sense (i.e., “may” rather than an obligatory sense (i.e., “must”). Similarly, the words “include,” “including,” and “includes” mean “including, but not limited to.” Where used in the claims, the term “or” is used in an inclusive sense (i.e., “or” rather than an exclusive sense (i.e., “or”). For example, the phrase “at least one of x, y, or z” means any one of x, y, and z, and any combination thereof.

[0035] This disclosure relates to methods, apparatus, and systems for aligning the ends of optical elements and / or fixing the aligned ends of optical elements. For example, it may be necessary to align a first optical element (e.g., an optical fiber cable) with a second optical element (e.g., a waveguide for a quantum memory). This may be necessary to configure an optical device such as a quantum memory to receive photons, such as entangled photons, that represent quantum information to be stored in the quantum memory. Continuing the above example, aligned optical elements (e.g., optical fiber cables and waveguides) may need to be fixed to maintain their alignment while subjected to various changes in conditions, such as changes in thermal conditions or mechanical shocks. In some embodiments, the processes described herein may provide end alignment and fixing structures necessary to ensure that signal loss at the interface of aligned optical elements is minimized. The processes described herein may also ensure that external conditions such as temperature changes or mechanical shocks do not significantly alter the alignment or cause high signal loss at the aligned tapered ends of the optical elements. In some embodiments, the methods, apparatuses, and systems described herein may be used to align and fix optical elements of quantum devices, such as the quantum memory described above, but more generally, they may be used to align and fix optical elements of various other types of devices that receive light as input or provide optical signals as output. [Modes for carrying out the invention]

[0036] Structure for fixing aligned optical elements Figure 1 is a block diagram showing a process for fixing aligned tapered ends of optical elements forming an adiabatic bond according to several embodiments, the process including fixing at least one of the optical elements to an optical device structure with an adhesive and forming an additional fixing structure on the aligned tapered ends using a photoactive material and photolithography. Figure 2 is a flowchart showing the steps of a process for fixing aligned tapered ends of optical elements using a fixing structure formed using a photoactive material and photolithography according to several embodiments.

[0037] In some embodiments, a first step for forming a fixed coupling between optical elements includes aligning the tapered end of a first optical element with the tapered end of a second optical element, wherein the tapered ends of the first and second optical elements have complementary tapered shapes. For example, in step 1 of Figure 1 and block 202 of Figure 2, the tapered end 108 of optical element 102 is aligned with the tapered end 106 of optical element 104.

[0038] The next step for forming a fixed bond between optical elements is to fix a predetermined first or second optical element to the structure of the optical device, which is done by applying an adhesive to the predetermined first or second optical element and fixing it to the structure of the optical device. For example, in step 2 of Figure 1 and block 204 of Figure 2, the optical element 104 is fixed to the structure of the optical device using adhesive 110. In some embodiments, the optical element 102 may be a waveguide of the optical device, such as a waveguide on a quantum wafer 904 shown in Figure 9. The optical element 104 may also be an optical fiber 104 shown in Figure 9. In some embodiments, the adhesive 110 may fix the optical element 104 to a base or other structure of the optical device, such as a silicon base 902 of a quantum memory device 900 shown in Figure 9B. In some embodiments, the adhesive 110 may be an ultraviolet (UV) curing resin, such as epoxy, which hardens when irradiated with UV light. In some embodiments, the adhesive 110 may fix a free optical element, such as an optical fiber cable, to an optical device to which the free optical element is attached. For example, the optical fiber cable attached to the quantum memory may first be fixed by adhesive 110. While adhesive can provide a good structure for fixing optical elements, in some cases it may not be suitable for maintaining the alignment of optical elements 102 and 104 after mechanical or thermal shocks. Therefore, an additional fixing structure 114 may be added, as described in steps 3 and 4.

[0039] To form the additional fixation structure, in step 3 of Figure 1 and block 206 of Figure 2, aligned optical elements 102 and 104 having adiabatically bonded tapered ends 106 and 108 are immersed in the photoactive liquid polymer 112. Also, in step 4 of Figure 1 and block 208 of Figure 2, light is guided into the photoactive liquid polymer 112 to form the additional fixation structure 114. For example, in some embodiments, two-photon lithography as shown in Figure 3 may be used. The additional fixation structure 114 is formed by irradiating the photoactive liquid polymer with photons and is formed as an additional fixation structure 114 on the aligned tapered ends of the first and second optical elements (e.g., ends 106 and 108).

[0040] In some embodiments, optical elements fixed by adiabatically bonded by adhesive 110 and additional fixing structure 114 may have a signal loss of about 0.5 dB or less. Furthermore, adiabatically bonded alignment optical elements may be configured to cool to 70 Kelvin or below without losing alignment (and therefore without a significant increase in signal loss).

[0041] Figure 3 is a block diagram showing that, in several embodiments, photoactivation lithography is performed to form a fixed structure on the aligned tapered end of an adiabatic-coupled optical element.

[0042] In some embodiments, at least a portion of the optical device 308 is immersed in a photoactive polymer 306, and a set of bonded optical elements is fixed to the optical device 308. For example, optical element 310 is fixed to the optical device 308 by adhesive 318 and bonded to optical element 312, which is part of the optical device 308. Similarly, optical element 314 is fixed to the optical device 308 by adhesive 320 and bonded to optical element 316, which is part of the optical device 308.

[0043] To form the fixed structures 326 and 328, light beams 322 and 324 are directed towards appropriate positions along the coupled optical elements on which the fixed structures are to be formed. In some embodiments, two-photon lithography is used. In such a technique, the photoactive liquid polymer 306 hardens only at the point where two photons intersect, for example, where a light beam 322 directed in a first direction intersects with a light beam 324 directed in a second direction. In some embodiments, the first and second directions may be orthogonal to each other (e.g., vertical and horizontal directions). This technique makes it possible to precisely form the shapes of the fixed structures 326 and 328, such as the cylindrical shape shown in Figure 5 or the inverted hourglass shape shown in Figure 6, and to precisely position the fixed structures 326 and 328.

[0044] Figure 4 is a perspective view of an example of a fixing structure for fixing an adiabatic-coupled optical element formed using a photoactive material and photolithography, according to several embodiments.

[0045] In some embodiments, the fixed structure 114 may have lengths extending in either direction from the adiabatic coupling interface, as shown as lengths 404 and 406 in Figure 4. In some embodiments, lengths 404 and 406 may be centered on the adiabatic coupling interface and have a total length 408. In some embodiments, lengths 404 and 406 may be less than or equal to about 50 wavelengths, for example, about 25 wavelengths, where the wavelengths referenced in the measurement of lengths 404 and 406 are the wavelengths of light transmitted through the optical elements 102 and 104. The fixed structure 114 may also have a total length 408 of less than or equal to about 100 wavelengths, and in some embodiments, a total length of 50 wavelengths. However, in some embodiments, other length and diameter dimensions may be used. In some embodiments, the diameter and / or length may be selected to provide sufficient structural support without causing a significant discontinuity that affects the light transmitted through the optical elements 102 and 104. For example, if the diameter of the shields of the optical elements 102 and / or 104 changes abruptly and significantly, scratches that can scatter light may occur. In some embodiments, the thickness of the fixed structure 114 may be selected to provide sufficient structural support without causing light scattering, for example, due to scratches. For example, in some embodiments, the radius 402 may be about 10 wavelengths or less, for example, about 2.5 wavelengths, and the outer diameter of the fixed structure 114 may be about 20 wavelengths or less, for example, a diameter of about 5 wavelengths.

[0046] Figure 5 shows a side view of one example of a fixed structure having a cylindrical outer shape according to several embodiments, and Figure 6 shows a side view of one example of a fixed structure having an inverted hourglass-shaped outer shape.

[0047] For example, the fixing structure 114 may have a cylindrical shape 502 as shown in Figure 5, or an inverted hourglass shape 602 as shown in Figure 6. For example, the fixing structure 114 may have a cylindrical shape 502 centered on the aligned tapered ends of the first and second optical elements 102 and 104. Alternatively, as another example, the fixing structure 114 may have a radius that changes to form an inverted hourglass shape 602, with the thick central portion of the inverted hourglass shape aligned with the aligned tapered ends (e.g., 106 and 108) of the first and second optical elements 102 and 104, and the thickness of the additional fixing structure may decrease in a tapered manner in both directions from this thick central portion, as shown in Figure 6.

[0048] In some embodiments, multiple sets of optical elements connected to the same optical device may be fixed by a fixing structure as described herein. For example, Figure 7 shows a plan view of an optical device according to some embodiments in which one set of optical elements is adiabatically coupled to another set of optical elements, and a fixing structure formed by photoactivation lithography fixes the adiabatically coupled set of optical elements.

[0049] In some embodiments, the optical device 700 includes optical elements 704, 714, and 724, which are coupled to optical elements 702, 712, and 722, respectively. Optical elements 702, 712, and 722 are fixed to the optical device 700 via adhesive coating portions 706, 716, and 726, respectively. Each pair of optical elements is also fixed in an adiabatic coupling region by fixing structures 708, 718, and 728, which may be formed using photoactivated lithography as described in Figure 3. More specifically, as further described with respect to Figure 8, the optical device 700 may be a photonic wafer which is part of a quantum memory or quantum repeater, and the optical elements coupled to the optical device 700 may be optical fiber cables connected to the photonic wafer. As an example, the fixing structures described herein may be used to fix optical fiber cables to the waveguide of the optical device, such as in a waveguide / optical fiber interface. Furthermore, as shown in Figure 13, the fixing structures described herein may be used to fix optical connections, such as those in satellites that are subjected to mechanical vibrations and temperature changes during launch into space.

[0050] Figure 8 shows an example implementation of an optical device capable of transmitting light through adiabatic-coupled optical elements fixed using a fixed structure formed using photoactivation lithography, according to several embodiments.

[0051] In some embodiments, the photonic wafer 800 may be used to transmit light between an optical fiber 102 and each quantum memory that can be patterned within the photonic waveguide layer 802. In some embodiments, the process for manufacturing at least some regions of the photonic wafer 800 may use a start stack including a substrate 806 and photonic waveguide layers 802 and 804, and these waveguide layers 802 and 804 may be patterned to obtain the components shown in Figure 8. For example, the photonic coupling region 810 may represent a region of the photonic wafer 800 from which light can be transmitted between the photonic waveguide layer 804 and the photonic waveguide layer 802. As shown in Figure 8, the two photonic waveguide layers of the photonic coupling region 810 are tapered to enable evanescent coupling. In contrast, the waveguide / optical fiber interface 818 may represent a region of the photonic wafer 800 from which light can be transmitted between the optical fiber 104 and the photonic waveguide layer 804. In some embodiments, the optical fiber 104 may interface with the photonic waveguide layer 804 using an adiabatic coupling in which the tapered end 108 of the optical fiber 104 contacts the tapered end 106 of the waveguide element 102. In some embodiments, van der Waals forces may initially hold the tapered ends 106 and 108 together while the fixing structure 114 is applied. Alternatively, the adhesive 110 may fix the optical fiber 104 to the substrate 806.

[0052] In some embodiments, an optical switch network, such as an optical switch network 812, may be patterned within the material used to manufacture the photonic waveguide layer 804. The optical switch network 812 may be used to route photons between the waveguide / optical fiber interface 818 and the photonic coupling region 810. As shown in Figure 8, it may be advantageous to design the photonic wafer 800 so that a single optical fiber serves a number of individual quantum memories, and by addressing incident photons using the optical switch network 812, the photonic wafer 800 can be made into a high-density mounted device. In some embodiments, patterning the optical switch network 812 within the photonic waveguide layer 804 may be done in various ways. For example, in some embodiments where the material of the photonic waveguide layer 804 is selected based on its electro-optical properties, it may be advantageous to keep photons within the photonic waveguide layer 804 until it becomes necessary to transfer the light into the photonic waveguide layer 802 (e.g., into a predetermined quantum memory patterned within the photonic waveguide layer 802).

[0053] The photonic wafer 800 may be configured to receive superposition photons (e.g., photons via the optical fiber 104) into on-wafer memory units (e.g., each quantum memory patterned within the photonic waveguide layer 802, such as a single quantum memory 808). In some embodiments, the quantum memories patterned within the photonic waveguide layer 802 may be coupled to nanophotonic cavities, such as the nanophotonic cavity shown in the single quantum memory 808, where the single quantum memory 808 exemplifies silicon vacancies in a diamond structure. In such embodiments, the silicon vacancies are embedded within nanophotonic cavities in the photonic waveguide layer 802, in which case the waveguide layer 802 may be diamond. Silicon vacancies in a diamond structure, such as the single quantum memory 808 shown in Figure 8, can function as quantum memories, and the corresponding nanophotonic cavities (e.g., cavities patterned with diamond, etc.) may enable the silicon vacancies in the diamond structure to interface with light. However, in other embodiments, the quantum memory patterned within the photonic waveguide layer 802 may be similar to other structures embedded within the photonic waveguide layer 802, such as nitrogen vacancies in diamond, trapped atoms, ensemble-doped crystals, atomic vapors, silicon carbide emitters, single rare-earth dopants, trapped ions, superconducting qubits, quantum dots in gallium arsenide, or defect centers in silicon or other semiconductor materials. Furthermore, different types of quantum memory may be embedded in each portion of the photonic waveguide layer 802, and in some embodiments, different materials may be used for each photonic wafer region (e.g., photonic wafer region 912) of the quantum wafer 904, as shown in Figure 9B, thereby patterning each photonic waveguide layer according to a predetermined quantum memory architecture.

[0054] In embodiments in which the photonic wafer 800 is used in a quantum memory device such as a quantum memory device 900 used as a quantum network node for quantum entanglement distribution, the photonic wafer 800 may be configured to store the first received entangled particle of a first entangled particle pair in a first single quantum memory 808 of the photonic waveguide layer 802, and to store the second received entangled particle of a second entangled particle pair in a second single quantum memory 808 of the photonic waveguide layer 802.

[0055] The photonic wafer 800 (or a quantum measurement device connected to the photonic wafer 800 inside or outside the quantum memory device 900) may further be configured to perform one or more joint measurements on the first and second entangled particles without disrupting the superposition state of the first and second entangled particles. The joint measurements determine the correlation between the superposition states of the entangled particles, thereby making it possible to extend the entanglement between pairs of entangled particles.

[0056] In some embodiments, the quantum memory within the photonic waveguide layer 802 may be configured to herald, meaning that when a particle arrives and is stored in a single quantum memory such as a single quantum memory 808, the quantum measuring device emits a herald signal to indicate the arrival of the particle. In some embodiments, such a herald signal may be transmitted via the optical fiber 104 and used to trigger the operation of an optical switch in the optical switch network 812, thereby aligning the next path in the optical switch network 812 to route the next arriving particle to the corresponding quantum memory in the photonic waveguide layer 802. Also, although not shown, in some embodiments, the photonic wafer 800 may include multiple sets of optical switch networks and associated waveguide layers 802 and quantum memory 808. For example, each of the optical fibers 702, 712, and 722 shown in Figure 7 may be connected to an optical switching network having associated waveguides and quantum memories, as shown in Figure 8.

[0057] In some embodiments, the photonic wafer 800 may further include a conversion interface (e.g., a nonlinear optical element 814). For example, in some embodiments, the conversion interface (e.g., a nonlinear optical element 814) may convert the transmission frequency of received photon particles to a different frequency before storing the particles in a predetermined quantum memory within the photonic waveguide layer 802. For example, in some embodiments, an optical fiber link (e.g., an optical fiber 104) may transmit photon particles using different frequencies, and such variations may be regulated by the conversion interface of the photonic wafer 800. As another example, particles received on the photonic wafer 800 via an optical ground station and / or particles received on the photonic wafer 800 via an optical fiber link may be transmitted at different wavelengths, and the conversion interface of the photonic wafer 800 may convert the wavelength of the received particles to a wavelength that a predetermined single quantum memory, such as a single quantum memory 808, uses to store the quantum particles in the memory. In some embodiments, the nonlinear optical element 814 shown in Figure 8 may provide phase shift, amplitude modulation and / or other functions with respect to the received particle, and / or provide any other interface characteristics that may be necessary for manipulating the incident particle before routing it to the memory on the photonic wafer 800. Furthermore, in some embodiments, as shown in Figure 8, the nonlinear optical element 814 may be manufactured using the same material as the material used to manufacture the photonic waveguide layer 804.

[0058] Figures 9A and 9B show an example implementation of an optical device, such as a quantum memory device (e.g., a quantum repeater), that can transmit light through adiabatic-coupled optical elements fixed using a fixed structure formed using photoactivation lithography, according to several embodiments.

[0059] In some embodiments, the quantum memory may provide a method for receiving, storing, and providing quantum information. In some cases, the quantum memory may be deployed in large-scale optical fiber networks and / or quantum entanglement networks, for example as a quantum repeater, to store and effectively connect dispersed entangled particles to provide secure long-distance communication. In such applications, the quantum memory device 900 may perform the function of controlling the tuning of the quantum memory housed within the quantum memory device 900 (e.g., adjustment of the local electrical, optical, thermal, and electromechanical environment).

[0060] In some embodiments, a quantum memory device, such as quantum memory device 900, may include a quantum memory and a quantum memory control device. For ease of explanation, some embodiments described below will be illustrated using a quantum memory device 900 analogous to a quantum repeater as an example. However, in some embodiments, the quantum memory device described herein in Figures 9A and 9B may be used for other purposes, such as locally storing quantum information at a given location. For example, in some situations, the quantum memory device 900 may be used to store quantum information (such as for use as a cache) used by multiple locally located quantum computers. As seen in Figures 9A and 9B, the quantum wafer 904 may house quantum memories via a photonic wafer region, such as a photonic wafer region 912. The photonic wafer region 912 may be analogous to a photonic wafer 800 and may have the functions described herein for the photonic wafer 800 (e.g., the function of routing light between optical fibers and the respective quantum memories of the photonic wafer 800).

[0061] The quantum memory control device of the quantum memory apparatus 900 may, for example, provide a mechanism for receiving and routing quantum information (e.g., entangled particles) to be stored in the quantum memory of the quantum wafer 904. In another example, the quantum memory control device may provide a mechanism for receiving, transmitting, emitting, and / or controlling optical and / or electrical control signals to or from the quantum wafer 904. In yet another example, the quantum memory control device may modify the behavior of the quantum memory on the quantum wafer 904 by using low-frequency control signals (e.g., microwave, RF, and / or DC control signals) that can induce strain in the quantum memory. The quantum memory control device may further control the flow of heat and / or gas to the quantum wafer 904. In some embodiments, the quantum memory control device may be used to supply electrical control signals that generate a local electromechanical strain field near the quantum memory on the quantum wafer 904. Such an electromechanical strain field may, for example, enable tuning of the optical and / or spin properties of the quantum memory on the quantum wafer 904 to improve the performance and operation of the quantum memory. In some embodiments, this may be referred to as strain tuning of quantum memory.

[0062] The arrangement and interaction of the quantum memory and some quantum memory control devices within the quantum memory device 900 may be similar to the embodiments shown in the side view and top view of the quantum memory device 900 in Figures 9A and 9B, respectively. In some embodiments, the quantum memory device 900 may further include optical fiber ports and / or electrical ports that provide access points between the quantum wafer 904 and optical fiber cables, control signal leads, wires, electrical cables, etc., located outside the quantum memory device 900.

[0063] In some embodiments, the quantum memory device 900 may include a base material, such as a silicon base 902, to which a quantum wafer 904 can be bonded / attached. In some embodiments, as shown in Figures 9A and 9B, the base material is silicon. However, those skilled in the art should understand that the base material may be other materials (e.g., other semiconductor materials) that provide similar functionality to the silicon base 902. In some embodiments, optical fibers, such as optical fiber 906, may be inserted into grooves or through-holes formed within the silicon base 902. For example, the optical fiber 104 shown in Figure 1 may be inserted into a groove or through-hole formed within the silicon base 902. As shown in Figure 9B, the optical fiber 906 may be coupled to the quantum wafer 904 and the optical fiber port of the quantum memory device 900. In some embodiments, an adhesive 110 (shown in Figure 1) may fix the optical fiber to the silicon base 902, and a fixing structure 114 (shown in Figure 1) may fix the optical fiber to the waveguide of the quantum wafer 904. Depending on its depth, the silicon base 902 may accommodate multiple rows of optical fibers that fit into grooves. The silicon base 902 may be bonded (e.g., soldered) to the quantum wafer 904 (e.g., via indium bumps). In some embodiments, the optical fiber 906 may be called a “tapered” optical fiber because it has a needle-like shape as shown in Figure 9B.

[0064] In some embodiments, wire bonds, such as wire bonds 908 (e.g., soldering points), may be used to connect control signal leads 910 to electrical ports of the quantum memory device 900. In some embodiments, electrical connections to the quantum wafer 904 may be formed using a "flip-chip" method. In such embodiments, the "flip-chip" layer may allow routing of electrical signals with complex topologies to the quantum wafer 904. In some embodiments, electrical control signals, such as microwave or RF frequency control signals, may be used to control a given quantum memory state (e.g., state change). In some embodiments where the quantum memory on the quantum wafer 904 is a nanophotonic cavity (e.g., a single quantum memory 808), a DC or low-frequency AC electric field may be used to tune the color center resonance of such a nanophotonic cavity. In some embodiments, such electrical control signals may be configured to avoid crosstalk and overheating of the quantum memory on the quantum wafer 904. In some embodiments, electrical control signals, such as DC, RF, and / or microwave signals, may be supplied to the quantum memory of the quantum wafer 904 via finely patterned electrical lines (e.g., coplanar waveguides, capacitors, etc., made of semiconductor and / or superconducting materials) (e.g., control signal leads 910) on both the silicon base 902 and the quantum wafer 904. For example, such finely patterned electrical lines may be patterned using a photonic waveguide layer 804.

[0065] In some embodiments, the quantum wafer 904 may also contain other types of devices on the same wafer, and as a result, the quantum wafer can become a high-density packaging device. For example, a photon detector, a nonlinear optical element for frequency conversion (e.g., a nonlinear optical element 814), and / or an on-chip light source may be fabricated. In some embodiments, electromagnets may be provided on the quantum wafer 904 (e.g., as small “on-chip” electromagnets) to fine-tune the local magnetic field environment of the quantum memory. Such “on-chip” electromagnets may be patterned on the quantum wafer 904 via a photolithography and / or electron beam lithography fabrication process.

[0066] In some embodiments, the quantum memory on the quantum wafer 904 may be analogous to a single quantum memory 808, and may have the functions and / or various types of quantum memory described above with respect to the single quantum memory 808. In some embodiments, the quantum wafer 904 includes a "host material" (photonic waveguide layer 802) for the quantum memory and may be finely patterned for electrical lines that allow electrical control signals to reach the quantum memory. The material selected for the quantum wafer 904 may vary depending on the type of quantum memory that it hosts. For example, the quantum wafer 904 may be analogous to a nanophotonic crystal interface for a type of quantum memory such as a SiV color center in diamond. However, when accommodating other types of quantum memory, the quantum wafer 904 may be analogous to any nanophotonic cavity (e.g., a nanophotonic crystal cavity, a ring resonator, a plasmonic cavity, etc.) or Fabry-Perot cavity that provides an optical interface to the quantum memory of the quantum memory device 900. As described herein, the nanophotonic cavity may be mounted on various substrates such as diamond, LiNbO, or silicon.

[0067] Once the type of nanophotonic cavity is selected, a quantum memory control device in the interface layer 906 may be used to match the frequency of the nanophotonic cavity to a predetermined quantum emitter (e.g., an entangled particle source). For example, the quantum memory control device may be used to perform optical tuning (e.g., refractive index shift), electromechanical deformation tuning, and / or gas (e.g., N2 gas) deposition tuning on the nanophotonic cavity. Furthermore, control signal leads 910 may provide electrical control signals to and from the quantum memory and be connected to the quantum wafer 904 via wire bonds 908. In some embodiments, the control signal leads 910 may be routed to each nonlinear optical element 814 via an electrical wiring path 820 (e.g., an electrical connection patterned on the photonic wafer 800, e.g., a gold pad).

[0068] Figure 10 shows an example of a quantum memory device according to several embodiments, in which the quantum information storage device of the quantum memory device can receive photons via adiabatic coupled optical elements fixed using a fixed structure formed using photoactivation lithography.

[0069] The quantum memory device 1000 may include an input interface 1002 that receives particles in a superposition state into a quantum information storage unit 1004 including a single quantum memory 1006, and may be configured to be coupled to a Herald quantum measurement device 1008 via a photonic waveguide layer 1012. For example, the single quantum memory 1006 represents silicon vacancies in a diamond structure. However, in some embodiments, other structures such as nitrogen vacancies in diamond, trapped atoms, ensemble-doped crystals, atomic vapors, silicon carbide emitters, single rare-earth dopants, trapped ions, superconducting qubits, and quantum dots in gallium arsenide may be used. Furthermore, although the input interface 1002 shows one embodiment of a time-bin qubit coding-transformation module, other embodiments having other input interface configurations, including wavelength or mode matching, may be used.

[0070] In some embodiments, the input interface 1002 may be configured to couple to the photonic waveguide layer 1010 using, for example, the tapered end adiabatic coupling and fixing structure shown in Figure 1. For example, the input interface 1002 may receive an optical fiber 104 and adiabatically couple the optical fiber 104 to the optical element 102 of the photonic waveguide 1012. This may be done using the adhesive 110 and fixing structure 114 shown in Figure 1.

[0071] In some embodiments, the quantum memory device 1000 may be configured to store quantum information corresponding to the first received entangled particle of the first entangled particle pair in the first single quantum memory 1006 of the quantum information storage unit 1004, and further to store quantum information corresponding to the second received entangled particle of the second entangled particle pair in the second single quantum memory 1006 of the quantum information storage unit 1004. The quantum memory device 1000 may also be configured to perform one or more joint measurements on the first and second particles via the Herald quantum measurement device 1008 in a manner that does not disrupt the superposition state of the first and second entangled particles. The joint measurements determine the correlation between the superposition states of the entangled particles, thereby making it possible to extend the entanglement between the entangled particle pairs.

[0072] The quantum memory device 1000 may be configured to herald, meaning that when a particle arrives at the quantum memory device 1000, the quantum measurement device 1008 (or another device coupled to the quantum information storage unit 1004 of the quantum memory device 1000) emits a herald signal to indicate the arrival of the particle. In some embodiments, such a herald signal may be used to operate an optical switch to align the switch and cause the quantum memory to receive the next particle from the entangled particle source to which the quantum entanglement should be distributed. Furthermore, when a second particle arrives at the quantum memory device 1000 from the entangled particle source, a second herald signal may be emitted. This second herald signal may then cause a joint measurement to be performed on the first and second particles stored in the quantum memory device 1000. Furthermore, the entanglement may be extended by the joint measurement (see also the description relating to Figure 12). In some embodiments, the quantum measurement device 1008 may perform herald measurements and joint measurements, and in some embodiments, different quantum measurement devices 1008 may be used to perform herald measurements and joint measurements on a pair of receiving particles. In some embodiments, the herald function may be performed by a quantum non-destructive measurement device that can detect the incidence of a particle (e.g., a photon) into the quantum memory device 1000 without causing the particle to collapse from a superposition state.

[0073] In some embodiments, the quantum memory device 1000 may further include a conversion interface. For example, in some embodiments, the conversion interface may convert the transmission frequency of the received particles to another frequency. For example, in some embodiments, an optical fiber link may transmit particles using different frequency wavelengths, and such variations may be adjusted by the conversion interface of the quantum memory device 1000. In some embodiments, the conversion interface may be located near the quantum memory device 1000, but it does not necessarily have to be included in the quantum memory device 1000.

[0074] In some embodiments, the quantum memory device 1000 (or set of quantum memories) may store a redundant set of particles for use in generating the distributed quantum entanglement. In such embodiments, the quantum memory may perform error correction by comparing the results of joint measurements of multiple sets of particles. Such error correction may, in some embodiments, function as entanglement purification. Alternatively, the parties at endpoints connected via the redundantly distributed quantum entanglement may perform error correction.

[0075] Figures 11A and 11B show optical devices, such as quantum memory devices, equipped with adiabatic coupled optical elements fixed using a fixed structure formed by photoactivation lithography, installed in a cryogenic cooling device, according to several embodiments.

[0076] In some embodiments, one or more optical devices, such as a packaged quantum memory device 1100, may be housed within a cryogenic cooler, such as a cryogenic cooler 1108. In some embodiments, the cryogenic cooler 1108 may be analogous to a dilution refrigerator, a cryogenic refrigerator, a cryogenic cooling element, a cryogenic cooler, and / or any system that cools to cryogenic temperatures and maintains that temperature over a period of time. Those skilled in the art will understand that the cryogenic cooler 1108 is configured to operate at different temperatures and / or different temperature ranges, such as within a cryogenic range and a higher temperature range (e.g., near room temperature, above room temperature, etc.), and further configured to be able to stabilize at any temperature within a given temperature range. As shown in Figure 11B, the packaged quantum memory device 1100 may be completely housed within the cryogenic cooler 1108 as part of an installation process at the installation site (e.g., the location of a quantum network node for quantum entanglement distribution services).

[0077] In some embodiments, installing the packaged quantum memory device 1100 in the cryogenic cooler 1108 may include connecting optical fibers and electrical connectors to the corresponding optical fiber port and electrical port of the packaged quantum memory device 1100, such as the optical fiber port 1102 and the electrical port 1106. Installing the packaged quantum memory device 1100 in the cryogenic cooler 1108 may further, in some embodiments, include routing gas tubes, such as gas tube 1104, to and / or through gas tube connections.

[0078] In some embodiments, an additional fixing structure 114 (shown in Figure 1) provided on the aligned tapered ends (106 and 108) of the first and second optical elements (102 and 104) is configured to maintain the alignment of the tapered ends of the first and second optical elements while experiencing temperature cycles from room temperature to cryogenic temperatures. The additional fixing structure 114 (shown in Figure 1) provided on the aligned tapered ends (106 and 108) of the first and second optical elements (102 and 104) is also configured to withstand mechanical shocks from drops or vibrations during transport of the optical apparatus including the aligned and fixed first and second optical elements.

[0079] Figure 12 is an illustrative diagram showing how entanglement is extended by performing joint measurements of the received particles of each set of entangled particles distributed via an optical fiber network link, such as between a quantum memory device, in some embodiments.

[0080] In some embodiments, a joint measurement, as shown in Figure 12, may be performed on photons stored in a quantum memory within a quantum memory device, such as the quantum memory device 1000 (e.g., a single quantum memory 1006). For example, in step 1, a joint measurement is performed on two particles (e.g., photons) to determine whether the two particles are the same or opposite (e.g., whether they are in the same quantum state). This is done without revealing any information about the individual particles. Next, in step 2, entangled pairs are defined by their correlation, e.g., opposite or identical. In the example shown in Figure 12, both A / B and C / D are entangled to be opposite to each other. Next, in step 3, a joint measurement is performed on B / C to obtain a result (e.g., opposite or identical), and in the example shown in Figure 12, the result is opposite. From this, A knows that its complement is opposite to D's complement, and A and D can infer that they are in opposite states to each other. Subsequently, this information is used to process A / D in step 4, thereby entangling particles A and D so that they are always in opposite states. In some embodiments, the joint measurement may be performed using a local two-qubit gate (e.g., a CNOT gate) between B and C, and may also include measuring each bit individually. This can be understood as an entanglement generation operation and measurement, or conversely, as a single measurement in an "entangled basis". When the joint measurement is performed in this manner, the result reveals information about the correlation between particles such as particles B and C, but not about the particles themselves. This is due to the entanglement generated by the two-qubit operation. Such joint measurements may be performed in a quantum measurement device in some embodiments.

[0081] Figure 13 shows an example of an optical device in a satellite communication system or the like, according to several embodiments, and the optical device may include adiabatic coupled optical elements fixed using a fixed structure formed using photoactivation lithography.

[0082] The examples described in Figures 8 to 12 relate to quantum entanglement distribution, quantum memory, quantum repeaters, etc., but in some embodiments, fixed structures such as the structure 114 formed using the adhesive 110 and photoactivation lithography described herein may be used for more general applications, such as fixing optical elements in optical communication networks.

[0083] As an example, Figure 13 shows a satellite 1300 including a communication board 1308 connected to an optical transmitter 1304 and / or an optical receiver 1306. The optical elements 104 of the optical transmitter 1304 and the optical elements 104 of the optical receiver 1306 may be adiabatically coupled to the optical elements 102 of the communication board 1308, respectively. The adiabatically coupled optical elements are each fixed using an adhesive 110 and an additional fixing structure 114 formed using photoactivation lithography, as described in Figure 1 and throughout this specification.

[0084] The fixed structures 110 and 114 can fix the adiabatic coupling between optical elements even in the event of vibration and / or temperature changes. For example, the satellite 1300 may be launched into space by a rocket 1300, and the fixed structures 110 and 114 may fix the adiabatic coupling between the optical elements of the communication board 1308 and the optical transmitter 1304 and optical receiver 1306 during and after the launch process.

[0085] Process and system for aligning optical elements In some embodiments, an optical element alignment device may be used to align the tapered ends of optical elements to form an adiabatic coupling. For example, the alignment of optical elements to be fixed as described above may be performed using the optical element alignment device and procedure described herein. In some embodiments, the optical element alignment device may include an electrically controllable mount containing a piezoelectric or electrostatic material, which allows individual optical elements to be adjusted by very small distances (e.g., vertically or horizontally) in increments of, for example, 1 to 5 micrometers. Once the optical fibers are positioned close enough to each other, van der Waals forces may hold the tapered ends together while further fixing processes are performed, as described above with respect to Figure 1.

[0086] A challenge in aligning optical elements is that adiabatic fiber-device interfaces initially require extremely precise alignment between the fiber and the device. This alignment is on the scale of hundreds of nanometers, which is too fine to achieve even with the best classical fabrication and self-alignment techniques. Furthermore, the fiber taper itself is very delicate and cannot be driven by applying excessive force to the substrate, as this would cause damage. Therefore, there is a need for an optical element alignment apparatus and method, such as those described herein, that can individually actuate each fiber in a fiber array and gently bring it into contact with the target optical device. Once good contact is established, the fiber is naturally held in place by van der Waals forces, which naturally tend to hold materials together. If contact or coupling is insufficient, the optical element alignment apparatus can be used to separate the fiber from the device and attempt contact again. Ultimately, good contact is achieved, and the fiber remains fixed in place. In some embodiments, the optical element alignment apparatus uses a piezoelectric material that expands or contracts when a voltage is applied. By surrounding each fiber with a piezoelectric drive unit, the fiber can be pushed or pulled by a small distance within a 2D plane.

[0087] Figure 14A shows a perspective view of a block diagram of an optical element alignment device comprising a movable platform and individual electrically controllable optical element mounts included on the movable platform, according to several embodiments.

[0088] In some embodiments, an optical element alignment device, such as the optical element alignment device 1402, includes a platform 1404 and a platform actuator 1406. The platform actuator 1406 is configured to perform platform operations 1440, which may include rotations that adjust pitch, roll, and yaw, i.e., rotations around the X, Y, and Z axes, in addition to translational movements in three-dimensional dimensions such as X, Y, and Z. Furthermore, the platform 1404 includes a plurality of individually controllable mounts, such as an electrically controllable mount 1408. A first set of optical elements 1401 is loaded onto the electrically controllable mount 1408 and adjusted to couple with a second set of optical elements 1412. The second set of optical elements 1412 may be contained in an optical device 1414 (e.g., a photonic wafer 800 and / or a quantum wafer 904).

[0089] Figure 14B shows a plan view of a block diagram of an optical element alignment device comprising a movable platform and individual electrically controllable optical element mounts included on the movable platform, according to several embodiments.

[0090] In some embodiments, each of the electrically controllable mounts 1408 is individually controllable to perform individual optical element adjustments 1450, for example, vertical or horizontal adjustments, or adjustments in the Y and Z directions (where X represents the depth direction along the axis of the optical element). In the first stage, the platform actuator 1406 may adjust the platform 1404 so that the tapered ends of the first set of optical elements 1410 are adjacent to or in contact with the tapered ends of the second set of optical elements 1412. In some embodiments, depth adjustment in the X direction may be performed using the platform actuator 1406. In the second stage, after the platform has been adjusted and the first set of optical elements 1410 and the second set of optical elements 1412 are in contact with or adjacent to each other, individual adjustments for each optical element may be performed by the electrically controllable mounts 1408 to improve the alignment of each pair of optical elements that are coupled together. In some embodiments, the optical element may be formed from a thin tapered diamond, lithium niobate, aluminum nitride, silicon, silicon nitride, or other types of optical fiber cables. In some embodiments, hydrofluoric acid or ion beam milling may be used to form tapered ends on the optical element, such as tapered ends 106 and 108 shown for optical elements 102 and 104 in Figure 1.

[0091] For example, an electrically controllable mount 1440 may adjust optical element 1422 to align with optical element 1432, while an electrically controllable mount 1442 may independently adjust optical element 1424 to align with optical element 1434, and furthermore, an electrically controllable mount 1444 may independently adjust optical element 1426 to align with optical element 1436. In some embodiments, the electrically controllable mounts 1440, 1442, and 1444 may be adjusted simultaneously, or each optical element (e.g., optical elements 1422, 1424, and 1426, respectively) may be adjusted in different directions during a single adjustment cycle. In some embodiments, the adjustment of individual optical elements may have a precision granularity an order of magnitude smaller than the finest adjustment step achievable by the platform actuator 1406. For example, the adjustment precision of an electrically controllable mount 1408 may be on the order of 500 nanometers or less, and in some embodiments, it may be on the order of 100 nanometers or less.

[0092] Figure 15 is a flowchart illustrating the steps of a process for aligning the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements using an optical element alignment device comprising a movable platform and individual electrically controllable optical element mounts included on the movable platform, according to several embodiments.

[0093] In block 1502, each of the first set of optical elements, such as optical elements 1422, 1424, and 1426 of the first set of optical elements 1410, is mounted on an electrically controllable mount, such as electrically controllable mounts 1440, 1442, and 1444. In some embodiments, the first set of optical elements may be fiber optic cables. The electrically controllable mounts are part of a movable platform, such as a movable platform 1404 controlled by a platform actuator 1406. The movable platform is configured to move in three-dimensional (3D) space to align the first set of optical elements with a second set of optical elements, such as optical elements 1432, 1434, and 1436 of the second set of optical elements 1412. The electrically controllable mounts are configured to perform individual adjustments, such as individual adjustments 1450, to fine-tune the alignment of individual pairs of optical elements in the first and second sets of optical elements.

[0094] In block 1504, the movable platform is operated so that the tapered ends of the optical elements of the first set of optical elements are positioned adjacent to or in contact with the tapered ends of the optical elements of the second set of optical elements, and the first set of optical elements is coupled to the second set of optical elements.

[0095] In block 1506, after the platform has been sufficiently adjusted and positioned so that the tapered ends of the optical elements of the first set of optical elements are adjacent to or in contact with the tapered ends of the optical elements of the second set of optical elements, the movable platform may be locked in place or otherwise held stationary while individual adjustments are being made using the electrically controllable mount 1408.

[0096] In block 1508, the positions of individual optical elements of the first set of optical elements, for example, optical elements 1422, 1424, and 1426, are adjusted vertically and / or horizontally so that they are better aligned with the corresponding optical elements of the second set of optical elements. This is done using electrically controllable mounts 1440, 1442, and 1444. For example, as shown in Figures 20 and 21, individual adjustments to different optical elements may be performed simultaneously at different time points, and the individual adjustments may adjust different optical elements in different directions simultaneously or at subsequent time points.

[0097] Figures 16A and 16B show that, in some embodiments, the movable platform of an optical element alignment device is adjusted vertically to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements.

[0098] As shown in Figures 16A and 16B, the platform actuator 1406 may adjust the platform 1404 vertically (for example, in the Z direction) to align the tapered end of the first set of optical elements 1410 with the tapered end of the second set of optical elements 1412.

[0099] Figures 17A and 17B show that, in some embodiments, the movable platform of an optical element alignment device is adjusted horizontally to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements.

[0100] As shown in Figures 17A and 17B, the platform actuator 1406 may adjust the platform 1404 horizontally (for example, in the Y direction) to align the tapered end of the first set of optical elements 1410 with the tapered end of the second set of optical elements 1412.

[0101] Figures 18A and 18B show that, in some embodiments, the movable platform of an optical element alignment device is adjusted in the depth direction to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements.

[0102] As shown in Figures 18A and 18B, the platform actuator 1406 may adjust the platform 1404 in the depth direction (for example, the X direction) to align the tapered end of the first set of optical elements 1410 with the tapered end of the second set of optical elements 1412.

[0103] Figures 19A and 19B show that, in some embodiments, the movable platform of an optical element alignment device is rotated to align the tapered ends of a first set of optical elements with the tapered ends of a second set of optical elements.

[0104] As shown in Figures 19A and 19B, the platform actuator 1406 may rotate the platform 1404 to adjust the pitch, roll, and / or yaw (e.g., rotation around the X, Y, and / or Z axes) of the platform 1404, and align the tapered end of the first set of optical elements 1410 with the tapered end of the second set of optical elements 1412.

[0105] Figure 20 is a block diagram showing components of an electrically controllable optical element mount, including a piezoelectric material configured to individually adjust the position of a single optical element in at least two directions, according to several embodiments.

[0106] In some embodiments, the electrically controllable mount 1408 includes orthogonally arranged piezoelectric actuators 2002 and 2004, as shown in Figure 20. Each piezoelectric actuator may have its own control lines, such as vertical adjustment control 2006 and horizontal adjustment control 2008. As further illustrated in Figures 25 and 26, a control computer for the optical alignment device (e.g., a controller) may determine the individual vertical and horizontal adjustments to be made for each optical fiber and control the piezoelectric actuators 2002 and 2004 via the vertical and horizontal control lines 2006 and 2008.

[0107] Figure 21 is a block diagram showing a cross-sectional view of a movable platform of an optical element alignment device, in which multiple electrically controllable optical element mounts are mounted on the movable platform, according to several embodiments.

[0108] As shown in Figure 21, multiple electrically controllable mounts 1440, 1442, and 1444 may be mounted on the common platform 1304. The electrically controllable mounts 1440, 1442, and 1444 are individually controllable, and as a result, different electrically controllable mounts 1440, 1442, and 1444 can be controlled to adjust in different directions simultaneously with other mounts.

[0109] Figure 22 shows that, according to several embodiments, a first set of distinct movements distinct from each other are applied at a first time point via different electrically controllable optical element mounts mounted on a movable platform.

[0110] For example, in Figure 22, at a certain time M, the electrically controllable mount 1440 adjusts a predetermined optical element 104 to the right, the electrically controllable mount 1442 adjusts another predetermined optical element 104 upward, and the electrically controllable mount 1444 adjusts yet another predetermined optical element 104 to the left.

[0111] Figure 23 shows that, in several embodiments, different sets of individual movements are applied at subsequent time points via different electrically controllable optical element mounts mounted on a movable platform.

[0112] As shown in Figure 23, at a subsequent time, for example, time M+N, the electrically controllable mount 1440 adjusts a predetermined optical element 104 upward, the electrically controllable mount 1442 adjusts another predetermined optical element 104 upward, and the electrically controllable mount 1444 adjusts yet another predetermined optical element 104 to the right.

[0113] Thus, it can be seen that adjustments to individual optical elements can be performed simultaneously in different directions via electrically controllable mounts 1440, 1442, and 1444.

[0114] Figure 24 is a flowchart showing the first step of a process in which the tapered ends of a first set of optical elements are aligned with the tapered ends of a second set of optical elements using an optical element alignment device according to several embodiments.

[0115] In block 2402, a movable platform, such as movable platform 1404, is positioned such that an optical element mounted on an electrically controllable mount of the movable platform is adjacent to a second set of optical elements.

[0116] In block 2404, the controller of the optical element alignment device causes one or more images of the alignment state of the platform and a first set of optical elements relative to a second set of optical elements. Next, in block 2406, the controller of the optical element alignment device uses machine vision to determine one or more platform adjustments to improve the alignment. In some embodiments, the controller may further use machine vision to determine the taper shape of the tapered ends of the first set of optical elements and the tapered shape of the tapered ends of the second set of optical elements, the taper position of the tapered ends of the first set of optical elements and the taper position of the tapered ends of the second set of optical elements, and / or the taper angle of the tapered ends of the first set of optical elements and the taper angle of the tapered ends of the second set of optical elements.

[0117] Next, in block 2408, the controller of the optical element alignment device adjusts the platform in the vertical, horizontal, depth, and / or pitch, roll, or yaw directions using one or more actuators, such as the platform actuator 1406. In block 2410, the controller of the optical element alignment device captures one or more images of the alignment state of the adjusted platform and the first set of optical elements relative to the second set of optical elements. In block 2412, the controller of the optical element alignment device determines whether the platform adjustment has been sufficiently performed until the misalignment between the tapered ends of the first set of optical elements and the tapered ends of the second set of optical elements is less than a first threshold misalignment amount. If not, additional adjustments are made until the threshold is met. Once the threshold is met, in block 2414, the controller of the optical element alignment device proceeds to the second stage of alignment processing shown in Figure 25.

[0118] Figure 25 is a flowchart showing the second step of a process in which the tapered ends of a first set of optical elements are aligned with the tapered ends of a second set of optical elements using an optical element alignment device according to several embodiments.

[0119] In block 2502, the controller of the optical element alignment device causes light to be transmitted through a first and / or second set of optical elements to be aligned. In block 2504, the controller of the optical element alignment device causes images of the optical elements to be captured while the light passes through these optical elements. The captured images allow observation of light scattering at the misaligned tapered end. In blocks 2506, 2508, and 2510, individual adjustments to be performed by each electrically controllable mount (e.g., electrically controllable mounts 1440, 1442, and 1444) are determined based on the observed light scattering, and in blocks 2512, 2514, and 2516, each electrically controllable mount (e.g., electrically controllable mounts 1440, 1442, and 1444) is controlled to perform the determined adjustments.

[0120] In block 2518, the controller of the optical element alignment device captures another image while light passes through these optical elements and observes changes in light scattering. Next, in blocks 2520, 2522, and 2524, the controller determines whether each optical element is aligned to satisfy a second threshold based on the presence or absence of scattered light at the interface between the tapered ends of the corresponding optical elements. If the second threshold is not met for one or more optical elements, the process returns to the corresponding block 2506, 2508, or 2510 with respect to the optical element and is repeated until the second threshold is met. Once the second threshold is met, the process proceeds to the third alignment stage. In some embodiments, the alignment of some optical elements may proceed to the third stage while further adjustments based on light scattering are being made to other optical elements as part of the second stage.

[0121] Figure 26 is a flowchart showing the third step of a process in which the tapered ends of a first set of optical elements are aligned with the tapered ends of a second set of optical elements using an optical element alignment device, according to several embodiments.

[0122] In blocks 2602, 2604, and 2606, optical signals are routed through optical elements aligned to satisfy a second threshold as described in Figure 25. Then, in blocks 2608, 2610, and 2612, signal loss is measured for each pair of aligned optical elements. In blocks 2614, 2616, and 2618, the controller of the optical element alignment device determines whether a third threshold is met based on the measured signal loss. If the third threshold is met, the process ends. Otherwise, additional individual adjustments are determined in blocks 2620, 2622, and 2624, and the adjustments are performed in blocks 2626, 2628, and 2630. This process may be repeated until the third threshold is met. For example, in some embodiments, the third threshold may be a threshold for the amount of signal loss, such as 0.5 dB or less.

[0123] Embodiments of this disclosure may be described pursuant to the following provisions. Clause 1. A method for forming a fixed coupling between optical elements, The alignment involves aligning the tapered end of the first optical element with the tapered end of the second optical element, such that the tapered ends of the first and second optical elements have complementary tapered shapes. Fixing one of the first or second optical elements to the structure of the optical device, wherein the fixing is performed by applying an adhesive to the predetermined first or second optical element and fixing it to the structure of the optical device. The first and second optical elements, which are aligned and at least partially fixed with adhesive, are immersed in a photoactive liquid polymer. By irradiating a photoactive liquid polymer with photons, an additional fixed structure is formed on the aligned tapered ends of the first and second optical elements, Methods that include... Clause 2. The method according to Clause 1, wherein aligning the tapered ends of the first and second optical elements forms an adiabatic coupling between the first and second optical elements. Article 3. The first and second optical elements, Fiber optic cable and Waveguides of optical devices, The method described in Clause 1 or Clause 2, comprising: Clause 4. With respect to multiple optical fiber cables coupled to each of the multiple waveguides of an optical device, perform the alignment, immersion, and formation of the additional fixing structure. The method described in Clause 3, further including the method described in Clause 3. Clause 5. The method of Clause 4, wherein the alignment, immersion, and formation of the additional fixing structure are performed in parallel for at least a portion of the plurality of waveguides of the optical device and the corresponding optical fibers. Clause 6. The method according to any one of Clauses 1 to 5, wherein the photoactive liquid polymer is irradiated with photons to form an additional fixed structure, and this is performed using a two-photon lithography process. Clause 7. The method according to any one of Clauses 1 to 6, wherein an additional fixing structure on the aligned tapered ends of the first and second optical elements is configured to experience a temperature cycle from room temperature to cryogenic temperatures while maintaining the alignment of the tapered ends of the first and second optical elements. Clause 8. The method according to any one of Clauses 1 to 7, wherein an additional fixing structure on the aligned tapered ends of the first and second optical elements is configured to withstand mechanical shocks caused by drops or vibrations during transport of the optical apparatus including the aligned and fixed first and second optical elements. Clause 9. An adhesive disposed to fix a first optical element to a structure of an optical device including a second optical element, wherein the tapered ends of the first optical element and the second optical element are aligned. An additional fixing structure formed on the aligned tapered ends of the first and second optical elements, the additional fixing structure being formed by irradiating a photoactive liquid polymer in which the aligned tapered ends of the first and second optical elements are immersed with photons, An optically coupled structure, including Clause 10. The optical coupling structure described in Clause 9, wherein the second optical element is a waveguide of an optical device and the first optical element is an optical fiber cable coupled to the optical device. Clause 11. The optical coupling structure according to Clause 9 or Clause 10, wherein the tapered ends of the first and second optical elements form an adiabatic coupling between the first and second optical elements. Clause 12. An optical coupling structure according to any one of Clauses 9 to 11, wherein the adhesive comprises an epoxy which is placed in liquid form on the casing of the first optical element and the structure of the optical device, and the epoxy hardens to fix the first optical element in place relative to the structure of the optical device. Clause 13. The additional fixing structure has a length that extends along the respective axes of the first and second optical elements, from the aligned tapered ends of the first and second optical elements in any direction, up to about 50 wavelengths, and the total length is up to about 100 wavelengths, the wavelengths corresponding to the wavelengths of light transmitted through the coupled first and second optical elements. An optical coupling structure as described in any of Clauses 9 to 12. Clause 14. The additional fixing structure has a radius perpendicular to the respective axes of the first and second optical elements, extending in either direction from the aligned tapered ends of the first and second optical elements by about 10 wavelengths or less, and having a total diameter of about 20 wavelengths or less, the wavelengths corresponding to the wavelengths of light transmitted through the coupled first and second optical elements. An optical coupling structure as described in any of Clauses 9 to 13. Clause 15. The additional fixing structure has a radius that changes to form an inverted hourglass shape, and the thick central portion of the inverted hourglass shape is aligned with the aligned tapered ends of the first and second optical elements, and the thickness of the additional fixing structure tapers away from this thick central portion in both directions. The optical coupling structure described in Clause 9. Clause 16. The additional fixing structure has a cylindrical shape centered on the aligned tapered ends of the first and second optical elements. The optical coupling structure described in Clause 9. Clause 17. Multiple additional adhesives arranged to fix multiple additional optical elements to a structure of an optical device, wherein the optical device includes multiple other optical elements that bond with the additional optical elements, and the tapered ends of the additional optical elements and the tapered ends of the other optical elements are aligned, A plurality of additional fixing structures formed on the aligned tapered ends of an additional optical element and other optical elements, which are formed by irradiating a photoactive liquid polymer in which the aligned tapered ends of the additional optical element and the tapered ends of other optical elements are immersed with photons, An optical coupling structure as described in any of Clauses 9 to 16, further comprising: Article 18. The first optical element and, A second optical element, An adhesive disposed to fix a first optical element to the structure of an optical device included in a photonic device, wherein the tapered ends of the first optical element and the second optical element are aligned; An additional fixing structure formed on the aligned tapered ends of the first and second optical elements, the additional fixing structure being formed by irradiating a photoactive liquid polymer in which the aligned tapered ends of the first and second optical elements are immersed with photons, Photonic devices, including those mentioned above. Clause 19. A photonic device is a quantum repeater or a photonic device containing a quantum repeater as described in Clause 18. Clause 20. A photonic device is a quantum memory or a photonic device containing a quantum memory as described in Clause 18. Clause 21. Mounting a first set of optical elements to a platform of an alignment device, wherein the platform is configured to move in 3D space, and each optical element of the first set of optical elements is individually mounted to the platform via each of a plurality of electrically controlled mounts mounted on the platform. The platform on which the first set of optical elements is mounted is operated so that the tapered ends of the first set of optical elements are positioned adjacent to or in contact with the tapered ends of the second set of optical elements to which the first set of optical elements is coupled. Using each electrically controlled mount, the positioning of each tapered end of the first set of optical elements is individually adjusted, and each tapered end of the first set of optical elements is aligned with the tapered end of the second set of optical elements. A method for aligning optical elements, including [the specified element]. Clause 22. The operation of the platform adjusts the positioning of the tapered ends of the first set of optical elements to a first level of precision. Individual adjustment of each tapered end via the electrically controlled mount adjusts the positioning of the tapered ends of the first set of optical elements to a second level of precision. The second precision level allows for adjustments that are an order of magnitude smaller than those possible with the first precision level. The method described in Article 21. Clause 23. The second level of precision is the method of Clause 21 or Clause 22, which allows for positional adjustments in increments of approximately 500 nanometers or less in a 2D plane orthogonal to the platform. Clause 24. The method according to any one of Clauses 21 to 23, wherein the electrically controlled mount includes a piezoelectric material or electrostatic device configured to individually adjust the positioning of the tapered ends of a first set of optical elements. Clause 25. The operation of the platform involves positioning the platform relative to the tapered ends of a second set of optical elements. Vertical direction, Horizontal, or Depth direction, The method described in any of clauses 21 to 24, including adjusting to the above. Clause 26. The operation of the platform involves positioning the platform relative to the tapered ends of a second set of optical elements. Around the X axis, Around the Y axis, or Around the Z axis, The method described in Clause 25, including adjusting to the following. Clause 27. The first step of a method for aligning optical elements includes manipulating the platform to adjust its pitch, roll and yaw, and further adjusting the platform's position relative to a second set of optical elements in the vertical, horizontal and depth directions. The second step of the method for aligning optical elements includes, while keeping the platform stationary, positioning the tapered ends of each of the first sets of optical elements in a 2D plane by the individual adjustments described above. The method described in Article 21. Clause 28. Obtain an image showing the relative positioning of the tapered end of the first set of optical elements with respect to the second set of optical elements, Using machine vision with acquired images, determine one or more platform movements to be performed as part of the operation of the platform, The method described in any of clauses 21 to 27, further including the method described in any of clauses 21 to 27. Article 29. Machine vision is, The tapered shape of the tapered end of the first set of optical elements and the tapered shape of the tapered end of the second set of optical elements, The tapered position of the tapered end of the first set of optical elements and the tapered position of the tapered end of the second set of optical elements, and / or Taper angle of the tapered end of the first set of optical elements and taper angle of the tapered end of the second set of optical elements The method described in Clause 28, which is configured to determine the method. Clause 30. Including light onto a first and / or second set of optical elements, the acquired image further includes showing light leakage or light scattering from the tapered ends of the first or second set of optical elements. The method according to Clause 28 or Clause 29, wherein machine vision determines one or more platform movements to be performed using light leakage or light scattering shown in the acquired images. Clause 31. Transmitting an optical signal from a transmitting device to a receiving device via a first and second set of adjacently arranged optical elements, Based on the measured signal characteristics, individual optical element adjustments are determined and performed via electronically controlled mounts. The method described in any of clauses 21 to 30, further including the method described in any of clauses 21 to 30. Clause 32. The method according to any one of Clauses 21 to 31, wherein the tapered ends of a first set of optical elements are adiabatically coupled to the tapered ends of a second set of optical elements by a method for aligning the optical elements. Clause 33. Fixing a predetermined optical element from a first or second set of optical elements to a structure of an optical device including the predetermined optical element, wherein the fixing is performed by applying an adhesive to the predetermined optical element and fixing it to the structure of the optical device. The method described in any of clauses 21 to 32, further including the method described in any of clauses 21 to 32. Clause 34. Immerse first and second sets of optical elements, which are aligned and at least partially fixed with corresponding adhesives, in a photoactive liquid polymer. By irradiating a photoactive liquid polymer with photons, additional fixed structures are formed on the aligned tapered ends of the first and second sets of optical elements. The method described in Article 33, further including the method described in Article 33. Clause 35. The first or second set of optical elements, Diamond optical device, Lithium niobate optical device, Aluminum nitride optical apparatus, Silicon optical devices, Silicon nitride optical device, or The method described in Clause 21, which is part of a fiber optic cable. Clause 36. A platform and actuators configured to move the platform in 3D space, An electrically controlled mount mounted on a platform, configured to hold individual optical elements of a first set of optical elements having tapered ends to be aligned with the tapered ends of a second set of electronic elements, An optical element alignment device, including one. Clause 37. Each electrically controlled mount shall A first piezoelectric material configured to adjust the position of each tapered end of an optical element in a first direction in a plane perpendicular to the platform, The system includes a second piezoelectric material configured to adjust the position of each tapered end of an optical element in a second direction in a plane perpendicular to the platform, The optical element alignment apparatus according to Clause 36, wherein the first direction and the second direction are orthogonal to each other. Clause 38. Obtain an image showing the relative positioning of the tapered end of the first set of optical elements with respect to the second set of optical elements, An optical element alignment apparatus according to Clause 36 or Clause 37, further comprising one or more computing devices that store program instructions configured to perform: determining one or more platform movements to be performed as part of the operation of the platform by machine vision using acquired images. Clause 39. Receiving information regarding an optical signal transmitted from a transmitting device to a receiving device via a first and second set of adjacently arranged optical elements, Based on the measured signal characteristics shown in the information, individual optical element adjustments are determined and performed via electronically controlled mounts. The optical element alignment apparatus described in Clause 38 further includes one or more computing devices that store program instructions configured to execute the optical element alignment apparatus. Clause 40. One or more non-temporary computer-readable storage media for storing program instructions, wherein when a program instruction is executed on or between one or more processors, one or more processors, Receiving an image captured to show the relative positioning of the tapered ends of a first set of optical elements with respect to a second set of optical elements, wherein the first set of optical elements is mounted on the platform via each of a plurality of electrically controlled mounts mounted on the platform, The process involves determining one or more platform movements to be performed using machine vision with acquired images, wherein the one or more platform movements involve positioning the tapered ends of a first set of optical elements adjacent to or in contact with the tapered ends of a second set of optical elements. Receiving information about an optical signal transmitted from a transmitting device to a receiving device via a first and second set of optical elements arranged adjacent to or in contact with each other, Based on the measured signal characteristics shown in the information, individual optical element adjustments are determined and performed via electronically controlled mounts. A storage medium that allows execution.

[0124] An example of a computer system Figure 27 is a block diagram showing an example of a computing device that may be used in at least some embodiments.

[0125] Figure 27 shows a general-purpose computer 2700 that may be used in any embodiment described herein. In the illustrated embodiment, the computer 2700 includes one or more processors 2710 coupled to system memory 2720 (which may include both non-volatile and volatile memory modules) via an input / output (I / O) interface 2730. The computer 2700 further includes a network interface 2740 coupled to the I / O interface 2730.

[0126] In various embodiments, the computing device 2700 may be a uniprocessor system including one processor 2710, or a multiprocessor system including multiple processors 2710 (e.g., two, four, eight, or any other appropriate number). The processor 2710 may be any suitable processor capable of executing instructions. For example, in various embodiments, the processor 2710 may be a general-purpose processor or embedded processor implementing various instruction set architectures (ISAs) such as x86, PowerPC, SPARC, or MIPS, or any other suitable ISA. In a multiprocessor system, each processor 2710 may, but is not necessarily, implement the same ISA. In some implementations, a graphics processing unit (GPU) may be used instead of, or in addition to, conventional processors.

[0127] The system memory 2720 may be configured to store instructions and data accessible by the processor 2710. In at least some embodiments, the system memory 2720 may include both a volatile portion and a non-volatile portion, while in other embodiments, only volatile memory may be used. In various embodiments, the volatile portion of the system memory 2720 may be implemented using any suitable memory technology, such as static random-access memory (SRAM), synchronous dynamic RAM, or any other type of memory. For the non-volatile portion of the system memory (which may include, for example, one or more NVDIMMs), in some embodiments, a flash-based memory device including a NAND flash device may be used. In at least some embodiments, the non-volatile portion of the system memory may include a power source such as a supercapacitor or other power storage device (e.g., a battery). In various embodiments, memristor-based resistive random-access memory (ReRAM), 3D NAND technology, ferroelectric RAM, magnetoresistive RAM (MRAM), or various types of phase-change memory (PCM) may be used in at least the non-volatile portion of the system memory. In the illustrated embodiment, program instructions and data that implement one or more desired functions, such as the methods, techniques, and data described above, are shown as being stored in system memory 2720 as code 2725 and data 2726.

[0128] In some embodiments, the I / O interface 2730 may be configured to coordinate I / O traffic between the processor 2710, system memory 2720, and any peripheral devices within the device (including network interface 2740 or other peripheral interfaces such as various types of persistent and / or volatile storage devices). In some embodiments, the I / O interface 2730 may perform necessary protocols, timing, or other data conversions to convert data signals from one component (e.g., system memory 2720) into a format usable by another component (e.g., processor 2710). In some embodiments, the I / O interface 2730 may support devices connected via various types of peripheral buses, such as variants of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard. In some embodiments, the functionality of the I / O interface 2730 may be divided into two or more separate components, such as a northbridge and a southbridge. Also, in some embodiments, some or all of the functionality of the I / O interface 2730, such as the interface to system memory 2720, may be directly integrated into the processor 2710.

[0129] The network interface 2740 may be configured to enable data exchange between the computing device 2700 and other devices 2760 connected to one or more networks 2750, such as other computer systems or devices shown in Figures 1 to 26. In various embodiments, the network interface 2740 may support communication over a suitable wired or wireless general-purpose data network, such as various Ethernet networks. Furthermore, the network interface 2740 may support communication over communication / telephone networks such as analog voice networks or digital optical fiber communication networks, storage area networks such as Fibre Channel SANs, or any other suitable type of network and / or protocol.

[0130] In some embodiments, the system memory 2720 may represent an embodiment of a computer-accessible medium configured to store at least some of the program instructions and data used to implement the methods and apparatus described in the context of Figures 1 to 26. However, in other embodiments, the program instructions and / or data may be received, transmitted, or stored on other types of computer-accessible media. Generally, the computer-accessible medium may include magnetic or optical media, non-temporary storage media or memory media such as disks or DVDs / CDs connected to the computer 2700 via the I / O interface 2730. The non-temporary computer-accessible storage medium may also include any volatile or non-volatile media such as RAM (e.g., SDRAM, DDR SDRAM, RDRAM, SRAM, etc.), ROM, etc., which may be included in some embodiments of the computer 2700 as the system memory 2720 or other types of memory. In some embodiments, multiple non-temporary computer-readable storage media may store program instructions distributed on these media, and the program instructions, when executed on one or more processors or between multiple processors, implement at least some of the methods and techniques described above. The computer-accessible medium may further include a transmission medium or signal, such as an electrical signal, an electromagnetic signal, or a digital signal, transmitted via a communication medium such as a network and / or a wireless link, and such a communication medium may be implemented via the network interface 2740. Some or all of the computing devices shown in Figure 27 may be used in various embodiments to implement the functions described, for example, by the cooperation of software components operating on various different devices. In some embodiments, some of the functions described may be implemented using a storage device, a network device, or a dedicated computer system in addition to or instead of a general-purpose computer system. As used herein, the term “computer device” refers to, but is not limited to, at least all of these types of devices.

[0131] conclusion Various embodiments may further include receiving, transmitting, or storing instructions and / or data implemented in accordance with the above description on a computer-accessible medium. Generally, computer-accessible media may include storage or memory media such as magnetic or optical media, such as disks and DVD / CD-ROMs, RAM (e.g., SDRAM, DDR, RDRAM, SRAM, etc.), volatile or non-volatile media such as ROM, as well as transmission media or signals such as electrical signals, electromagnetic signals, or digital signals transmitted via communication media such as networks and / or wireless links.

[0132] The various methods shown in the drawings and described herein represent exemplary embodiments of the methods. These methods may be implemented in software, hardware, or a combination thereof. The order of the methods may be changed, and various elements may be added, rearranged, combined, omitted, or modified.

[0133] Various modifications and changes may be made that would be obvious to those skilled in the art who have an interest in this disclosure. The present invention is intended to encompass all such modifications and changes, and therefore the above description should be interpreted as illustrative rather than restrictive.

Claims

1. A method for forming a fixed coupling between optical elements, The alignment involves aligning the tapered end of the first optical element with the tapered end of the second optical element, such that the tapered ends of the first and second optical elements have complementary tapered shapes. Fixing one of the first or second optical elements to the structure of the optical device, wherein the fixing is performed by applying an adhesive to the predetermined first or second optical element and fixing it to the structure of the optical device. The first and second optical elements, which are aligned and at least partially fixed by the adhesive, are immersed in a photoactive liquid polymer. By irradiating the photoactive liquid polymer with photons, an additional fixing structure is formed on the aligned tapered ends of the first and second optical elements. Methods that include...

2. The method according to claim 1, wherein aligning the tapered ends of the first and second optical elements forms an adiabatic coupling between the first and second optical elements.

3. The first and second optical elements are Fiber optic cable and Waveguides of optical devices, The method according to claim 1, comprising:

4. With respect to the multiple optical fiber cables coupled to each of the multiple waveguides of the optical device, the following steps are performed: alignment, immersion, and formation of the additional fixing structure. The method according to claim 3, further comprising:

5. The method according to claim 4, wherein the alignment, immersion, and formation of the additional fixing structure are performed in parallel with respect to at least a portion of the waveguide of the optical device and the corresponding optical fiber.

6. The method according to claim 1, wherein irradiating the photoactive liquid polymer with photons to form the additional fixed structure is performed using a two-photon lithography process.

7. The method according to claim 1, wherein the additional fixing structure on the aligned tapered ends of the first and second optical elements is configured to experience a temperature cycle from room temperature to cryogenic temperatures while maintaining the alignment of the tapered ends of the first and second optical elements.

8. The method according to claim 1, wherein the additional fixing structure on the aligned tapered ends of the first and second optical elements is configured to withstand mechanical shocks caused by drops or vibrations during transport of the optical apparatus including the aligned and fixed first and second optical elements.

9. An adhesive disposed to fix a first optical element to a structure of an optical device including a second optical element, wherein the tapered ends of the first optical element and the second optical element are aligned; An additional fixing structure formed on the aligned tapered ends of the first and second optical elements, the additional fixing structure being formed by irradiating a photoactive liquid polymer in which the aligned tapered ends of the first and second optical elements are immersed with photons, An optically coupled structure, including

10. The optical coupling structure according to claim 9, wherein the second optical element is a waveguide of the optical device, and the first optical element is an optical fiber cable coupled to the optical device.

11. The optical coupling structure according to claim 9, wherein the tapered ends of the first and second optical elements form an adiabatic coupling between the first and second optical elements.

12. The optical coupling structure according to claim 9, wherein the adhesive includes an epoxy that is placed in liquid form on the exterior of the first optical element and the structure of the optical device, and the epoxy hardens to fix the first optical element in a predetermined position relative to the structure of the optical device.

13. The additional fixing structure has a length that extends along the respective axes of the first and second optical elements, from the aligned tapered ends of the first and second optical elements in either direction, for a total length of about 50 wavelengths or less, and the wavelengths correspond to the wavelengths of light transmitted through the coupled first and second optical elements. The optical coupling structure according to claim 9.

14. The additional fixing structure is perpendicular to the respective axes of the first and second optical elements, extends in either direction from the aligned tapered ends of the first and second optical elements by about 10 wavelengths or less, has a radius with a total diameter of about 20 wavelengths or less, and the wavelengths correspond to the wavelengths of light transmitted through the coupled first and second optical elements. The optical coupling structure according to claim 9.

15. A plurality of additional adhesives arranged to fix a plurality of additional optical elements to the structure of the optical device, wherein the optical device includes a plurality of other optical elements that bond with the additional optical elements, and the tapered ends of the additional optical elements and the tapered ends of the other optical elements are aligned with the plurality of additional adhesives. A plurality of additional fixing structures formed on the aligned tapered ends of the additional optical element and the other optical elements, the plurality of additional fixing structures formed by irradiating a photoactive liquid polymer in which the aligned tapered ends of the additional optical element and the other optical elements are immersed with photons, The optical coupling structure according to claim 9, further comprising:

Images