Optical device and method of forming an optical device

Abstract

This application relates to an optical device and a method for forming such an optical device. Optical amplifiers, laser devices, and methods for forming such devices are disclosed. One such method includes: forming a lower cladding layer on a substrate and forming a doped ceramic layer on the lower cladding layer. The formation of the doped ceramic layer uses a plasma-assisted process of depositing ceramic material and co-doping the ceramic material with rare earth dopants; the method further includes: forming an upper cladding layer on the doped ceramic layer, and etching the upper cladding layer and the doped ceramic layer to form a doped ceramic waveguide.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application No. 63 / 743,384, filed January 9, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Various aspects of this disclosure relate to waveguide optical structures, such as waveguide optical amplifiers and laser devices. Background Technology

[0004] Conventional ceramic waveguide structures exhibit various drawbacks, at least in part, due to the conventional manufacturing processes used for such structures. For example, conventional ceramic waveguide structures may exhibit non-uniform doping densities and / or defects that limit the operational performance of such ceramic waveguides.

[0005] By comparing conventional and traditional methods with some aspects of this disclosure as set forth with reference to the accompanying drawings in the remainder of this application, those skilled in the art will clearly recognize the further limitations and disadvantages of such methods. Summary of the Invention

[0006] Ceramic waveguides, optical structures utilizing such ceramic waveguides (such as optical amplifiers and laser devices), and processes for manufacturing such optical structures and corresponding ceramic waveguides are shown and / or described in conjunction with at least one of the accompanying drawings and are set forth more fully in the claims. Such ceramic waveguides can exhibit a more uniform doping distribution and fewer defects than conventional ceramic waveguides.

[0007] These and other advantages, aspects and novel features of this disclosure, as well as details of its illustrated embodiments, will become more fully understood from the following description and drawings. Attached Figure Description

[0008] The various features and advantages of this disclosure can be more readily understood by referring to the following detailed embodiments in conjunction with the accompanying drawings, wherein the same reference numerals denote the same structural elements.

[0009] Figure 1 Embodiments of an integrated doped ceramic waveguide optical amplifier according to various aspects of this disclosure are described.

[0010] Figure 2 Embodiments of an integrated doped ceramic waveguide optical amplifier with an optical resonant cavity having pump light according to various aspects of this disclosure are described.

[0011] Figure 3 Embodiments of an integrated doped ceramic waveguide laser device according to various aspects of this disclosure are described.

[0012] Figure 4 Embodiments of an integrated doped ceramic waveguide laser device with an optical resonant cavity having pump light according to various aspects of this disclosure are described.

[0013] Figure 5 Depicting the fabrication of integrated ceramic optical structures (such as...) Figures 1 to 4 The flowchart of the process (structure).

[0014] Figures 6A to 6H Depicting the situation Figure 5 The cross-section of the integrated ceramic optical structure at each stage of the manufacturing process.

[0015] Figure 7A and Figure 7B Example implementations of a wavelength reference library according to various aspects of this disclosure are described. Detailed Implementation

[0016] The following discussion provides various examples of ceramic waveguides, optical structures utilizing such ceramic waveguides (such as optical amplifiers and laser devices), and processes for manufacturing such optical structures and corresponding ceramic waveguides. Such examples are non-limiting, and the scope of the appended claims should not be limited to the specific examples disclosed. In the following discussion, the terms "example" and "for example" are non-limiting.

[0017] The accompanying drawings illustrate a general construction method. To avoid unnecessarily obscuring this disclosure, descriptions and details of well-known features and techniques may be omitted. Furthermore, the elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to aid in understanding the examples discussed in this disclosure. The same reference numerals in different drawings denote the same elements.

[0018] The term "and / or" refers to any one or more items in a list connected by "and / or". As an example, "x and / or y" represents any element in the three-element set {(x), (y), (x, y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" represents any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, "x, y and / or z" means "one or more of x, y, and z".

[0019] The terms “comprises”, “comprising”, “includes”, and / or “including” are “open-ended” terms and specify the presence of the stated feature, but do not exclude the presence or addition of one or more other features.

[0020] The terms “first,” “second,” etc., may be used herein to describe various elements, and these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Thus, for example, a first element discussed in this disclosure may be referred to as a second element without departing from the teachings of this disclosure.

[0021] Unless otherwise specified, the term "coupled" can be used to describe two elements that are in direct contact with each other or to describe two elements that are indirectly connected through one or more other elements. For example, if element A is coupled to element B, then element A can be in direct contact with element B or indirectly connected to element B through an intermediate element C. Similarly, the terms "above" or "on top of" can be used to describe two elements that are in direct contact with each other or to describe two elements that are indirectly connected through one or more other elements.

[0022] Various implementations involve ceramic waveguides, optical structures utilizing such ceramic waveguides (such as optical amplifiers and laser devices), and processes for manufacturing such optical structures and corresponding ceramic waveguides. Such ceramic waveguides can exhibit a more uniform doping distribution and fewer defects than conventional ceramic waveguides.

[0023] Now for reference Figure 1 This paper describes an embodiment of an integrated doped ceramic waveguide optical amplifier 100 according to various aspects of the present disclosure. The optical amplifier 100 may include a pump light input 102, a wavelength division multiplexing (WDM) optical signal input 104, and a WDM optical signal output 106. The pump light input 102 of the optical amplifier 100 can receive pump light, and the WDM optical signal input 104 can receive a WDM optical input signal. Based on the received pump light and WDM optical input signal, the optical amplifier 100 can output a WDM optical signal via the WDM optical signal output 106, which is an amplified version of the WDM optical signal received via the WDM optical signal input 104.

[0024] For this purpose, the optical amplifier 100 may include a multiplexer 110, a doped ceramic waveguide 120, and a filter 130. The multiplexer 110 may include a pump light input 112, a WDM optical signal input 114, and a combined optical signal output 116. The pump light input 112 of the multiplexer 110 can receive pump light from the pump light input 102 of the optical amplifier 100. Similarly, the WDM optical signal input 114 of the multiplexer 110 can receive a WDM optical input signal from the WDM optical signal input 104 of the optical amplifier 100. Furthermore, the multiplexer 110 can combine the pump light and the WDM optical input signals and inject the combined optical signal into the doped ceramic waveguide 120.

[0025] The doped ceramic waveguide 120 may include a waveguide input 122 and a waveguide output 124. The doped ceramic waveguide 120 can receive combined optical signals from the multiplexer 110 via its waveguide input 122. In addition, the doped ceramic waveguide 120 can guide the combined optical signals to its waveguide output 124 and the filter 130.

[0026] As the combined optical signal propagates along the doped ceramic waveguide 120, the pump light can excite the rare-earth ions in the waveguide to a higher energy state. When photons from the WDM optical signal encounter the excited rare-earth ions, the ions may undergo stimulated emission and return to a lower energy state. During this return, the rare-earth ions can release their energy as additional photons, which are in the same phase and direction as the WDM optical signal. In this way, as the pump light and the WDM optical signal propagate along the length of the doped ceramic waveguide 120, the pump light and its interaction with the rare-earth ions can amplify the WDM optical signal. For this purpose, the ceramic material of the waveguide 120 can be doped with rare-earth atoms, such as erbium (Er), praseodymium (Pr), holmium (Ho), Ba, Sr, Ca, Yb, etc.

[0027] The ceramic material of the doped ceramic waveguide 120 can have a wide bandgap energy. For example, the bandgap energy of the doped ceramic waveguide 120 can be greater than or equal to 1.2 times the incident photon energy of the WDM optical signal or pump light. The ceramic material can also have a resistance greater than or equal to 1 M ohm-cm, and the refractive index of the ceramic material can be greater than or equal to that of the cladding material (e.g., Figures 6A to 6H The refractive index of the cladding material (610, 630, 640) is 1.1 times that of the substrate ceramic material of the doped ceramic waveguide 120. Therefore, the matrix ceramic material of the doped ceramic waveguide 120 can use base materials such as SiC, AlN, AlN, and AlN2. x O yThis is achieved by forming a ceramic matrix composite material containing materials such as Al2O3, BN, GaN, GaO, and LiNbO3, and dielectric materials such as SiN, SiNO, glass, and garnet. Such a material can form a doped ceramic waveguide 120 with a higher refractive index than the surrounding cladding material. Furthermore, such a material can provide low optical loss for the doped ceramic waveguide 120 at the operating wavelengths of the pump light and WDM optical signals. Depending on the operating wavelength and the optical gain provided by the pump light, many rare-earth dopants can be incorporated, such as erbium (Er), ytterbium (Yb), neodymium (Nd), praseodymium (Pr), holmium (Ho), and thulium (Tm). 3 + (e.g., adjusting optical properties to achieve optimal optical performance).

[0028] Furthermore, depending on the type of rare-earth dopant embedded in the doped ceramic waveguide 120, the optical amplifier 100, as well as other optical amplifiers and / or laser devices disclosed herein, can provide an amplification source or emission source operating at common wavelengths. For example, erbium dopant can generate signals for the 1500 nm telecommunications band, ytterbium (Yb) for the 1 μm band, neodymium (Nd) for the 1060 nm / 1300 nm band, praseodymium (Pr) for the 1300 nm band, and holmium (Ho) or thulium (Tm) for the 1 μm to 2 μm infrared band.

[0029] Filter 130 may include a combined optical signal input terminal 132 and a WDM optical signal output terminal 136. The combined optical signal input terminal 132 of filter 130 may receive a combined optical signal, including pump light and an amplified WDM optical input signal, from the doped ceramic waveguide 120. Filter 130 may reject, filter out, or reduce the received pump light so as to output a WDM optical signal, including the amplified WDM input signal received from the doped ceramic waveguide 120, via its WDM optical signal output terminal 136. Furthermore, filter 130 may provide the WDM optical signal to the WDM optical signal output terminal 106 of optical amplifier 100.

[0030] In various embodiments, multiplexer 110 and / or filter 130 may be implemented using undoped waveguide materials and / or waveguide materials different from ceramics. Therefore, multiplexer 110 and / or filter 130 may be implemented using waveguide materials different from the doped ceramic material used to implement doped ceramic waveguide 120.

[0031] In various embodiments, the optical amplifier 100, as well as other optical amplifiers and / or laser devices disclosed herein, can be designed to maximize the coupling efficiency between its facet and the external optical fiber. For example, the facet may be coated with a dielectric layer that provides an anti-reflective coating.

[0032] Now for reference Figure 2 Embodiments of an integrated doped ceramic waveguide optical amplifier 200 are described according to various aspects of this disclosure. The optical amplifier 200 may include a pump light input 202, a WDM optical signal input 204, and a WDM optical signal output 206. The pump light input 202 of the optical amplifier 200 can receive pump light, and the WDM optical signal input 204 can receive a WDM optical signal. Based on the received pump light and the received WDM optical signal, the optical amplifier 200 can output an amplified version of the received WDM optical signal via its WDM optical signal output 206.

[0033] For this purpose, the optical amplifier 200 may include a multiplexer 210, a doped ceramic waveguide 220, a demultiplexer 230, an optical signal combiner 240, and a ring cavity 250. The multiplexer 210 may include a pump light input 212, a WDM optical signal input 214, and a combined optical signal output 216. The pump light input 212 of the multiplexer 210 can receive pump light from the pump light output 246 of the optical signal combiner 240. Furthermore, the WDM optical signal input 214 of the multiplexer 210 can receive WDM optical signals from the WDM optical signal input 204 of the optical amplifier 200. Additionally, the multiplexer 210 can output a combined optical signal, including the pump light and the WDM optical signal, to the doped ceramic waveguide 220.

[0034] The doped ceramic waveguide 220 may include a waveguide input 222 and a waveguide output 224. The doped ceramic waveguide 220 can receive combined optical signals from the multiplexer 210 via its waveguide input 222. In addition, the doped ceramic waveguide 220 can guide the combined optical signals to its waveguide output 224 and the demultiplexer 230.

[0035] As the combined optical signal propagates along the doped ceramic waveguide 220, the pump light can excite the rare-earth ions in the waveguide to a higher energy state. When photons from the WDM optical signal encounter the excited rare-earth ions, the ions may undergo stimulated emission and return to a lower energy state. During this return, the rare-earth ions can release their energy as additional photons, which are in the same phase and direction as the WDM optical signal. In this way, as the pump light and the WDM optical signal propagate along the length of the doped ceramic waveguide 220, the pump light and its interaction with the rare-earth ions can amplify the WDM optical signal. For this purpose, the ceramic material of the waveguide 220 can be doped with rare-earth atoms, such as erbium (Er), praseodymium (Pr), holmium (Ho), Ba, Sr, Ca, Yb, etc.

[0036] The ceramic material used in the doped ceramic waveguide 220 can have a wide bandgap energy. For example, the bandgap energy of the doped ceramic waveguide 220 can be greater than or equal to 1.2 times the incident photon energy of the WDM optical signal or pump light. The ceramic material can also have a resistance greater than or equal to 1 M ohm-cm, and the refractive index of the ceramic material can be greater than or equal to that of the cladding material (e.g., Figures 6A to 6H The refractive index of the cladding material (610, 630, 640) is 1.1 times that of the substrate ceramic material of the doped ceramic waveguide 220. Therefore, the matrix ceramic material of the doped ceramic waveguide 220 can use base materials such as SiC, AlN, AlN, and AlN2. x O y It is formed by ceramic matrix composites of materials such as Al2O3, BN, GaN, GaO, and LiNbO3, as well as dielectric materials such as SiN, SiNO, and glass.

[0037] Demultiplexer 230 may include a combined optical input 232, a pump optical output 234, and a WDM optical signal output 236. The combined optical input 232 may receive a combined optical signal comprising an amplified version of the WDM optical signal and residual pump light from the doped ceramic waveguide 220. Demultiplexer 230 may demultiplex the residual pump light from the combined optical signal and direct it to its pump optical output 234 and the ring cavity 250. Similarly, demultiplexer 230 may demultiplex an amplified WDM optical signal from the combined optical signal and direct the amplified WDM optical signal to its WDM optical signal output 236 and the WDM optical signal output 206 of the optical amplifier 200.

[0038] The ring cavity 250 can receive residual pump light from the demultiplexer 230 and direct such residual pump light to the optical signal combiner 240. The optical signal combiner 240 may include a pump light input 242, a residual pump light input 244, and a pump light output 246. The pump light input 242 of the optical signal combiner 240 can receive pump light from the pump light input 202 of the optical amplifier 200, and the residual pump light input 244 of the optical signal combiner 240 can receive residual pump light from the ring cavity 250. The optical signal combiner 240 can combine the received pump light and residual pump light and direct the combined pump light to its pump light output 246 and the pump light input 212 of the multiplexer 210.

[0039] In various embodiments, the multiplexer 210, demultiplexer 230, optical signal combiner 240, and / or ring cavity 250 can be implemented using undoped waveguide materials and / or waveguide materials different from ceramics. Therefore, the multiplexer 210, demultiplexer 230, optical signal combiner 240, and / or ring cavity 250 can be implemented using waveguide materials different from the doped ceramic material used to implement the doped ceramic waveguide 220.

[0040] Now for reference Figure 3 This paper describes an embodiment of an integrated doped ceramic waveguide laser device 300 according to various aspects of the present disclosure. The laser device 300 may include a pump light input 302 and a WDM laser output 306. The pump light input 302 of the laser device 300 can receive pump light. Based on the received pump light, the laser device 300 can generate and output WDM laser light via its WDM laser output 306.

[0041] Therefore, the laser device 300 may include a multiplexer 310, a doped ceramic waveguide 320, a demultiplexer 330, and a wavelength reference library 360. The multiplexer 310 may include a pump light input terminal 312, a WDM optical signal input terminal 314, and a combined optical signal output terminal 316. The pump light input terminal 312 of the multiplexer 310 can receive pump light from the pump light input terminal 302 of the laser device 300. The WDM optical signal input terminal 314 of the multiplexer 310 can receive WDM optical signals from the wavelength reference library 360. Furthermore, the multiplexer 310 can output and inject a combined optical signal, including the pump light and the WDM optical signal, into the doped ceramic waveguide 320.

[0042] The doped ceramic waveguide 320 may include a waveguide input 322 and a waveguide output 324. The doped ceramic waveguide 320 can receive combined optical signals from the multiplexer 310 via its waveguide input 322. In addition, the doped ceramic waveguide 320 can guide the combined optical signals to its waveguide output 324 and the demultiplexer 330.

[0043] As the combined optical signal propagates along the doped ceramic waveguide 320, the pump light can excite the rare-earth ions in the waveguide to a higher energy state. When photons from the WDM optical signal encounter the excited rare-earth ions, the ions may undergo stimulated emission and return to a lower energy state. During this return, the rare-earth ions release their energy as additional photons, which are in the same phase and direction as the WDM optical signal. In this way, as the pump light and the WDM optical signal propagate along the length of the doped ceramic waveguide 320, the pump light and its interaction with the rare-earth ions can amplify the WDM optical signal. For this purpose, the ceramic material of the waveguide 320 can be doped with rare-earth atoms, such as erbium (Er), praseodymium (Pr), holmium (Ho), Ba, Sr, Ca, Yb, etc.

[0044] The ceramic material used in the doped ceramic waveguide 320 can possess a wide bandgap energy. For example, the bandgap energy of the doped ceramic waveguide 320 can be greater than or equal to 1.2 times the incident photon energy of the WDM optical signal or pump light. The ceramic material can also have a resistance greater than or equal to 1 ohm-cm, and the refractive index of the ceramic material can be greater than or equal to that of the cladding material (e.g., Figures 6A to 6H The refractive index of the cladding material (610, 630, 640) is 1.1 times that of the substrate ceramic material of the doped ceramic waveguide 220. Therefore, the matrix ceramic material of the doped ceramic waveguide 220 can use base materials such as SiC, AlN, AlN, and AlN2. x O y It is formed by ceramic matrix composites of materials such as Al2O3, BN, GaN, GaO, and LiNbO3, as well as dielectric materials such as SiN, SiNO, and glass.

[0045] The demultiplexer 330 may include a WDM optical signal input terminal 332, a WDM laser output terminal 336, and a WDM optical signal output terminal 338. The demultiplexer 330 can receive a combined optical signal, including residual pump light, an amplified version of the WDM optical signal, and the WDM laser, via its WDM optical signal input terminal 332. The demultiplexer 330 can demultiplex the combined optical signal and guide the WDM laser to the WDM laser output terminal 336 and the WDM laser output terminal 306 of the laser device 300. Furthermore, the demultiplexer 330 can guide the amplified WDM optical signal to the multiplexer 310 via its WDM optical signal output terminal 338 and the wavelength reference library 360.

[0046] Figure 7AA wavelength reference library 700A suitable for implementing wavelength reference library 360 is depicted. Specifically, wavelength reference library 700A may include a group or library of high-quality (Hi-Q) wavelength filters 710 and a wavelength tuning controller 720. Each Hi-Q wavelength filter 710 can transmit a portion of the light received from the input of wavelength reference library 700A that falls within a specified passband of the corresponding Hi-Q wavelength filter 710 to the output of wavelength reference library 700A. In this way, wavelength reference library 700A can provide a wavelength-selective feedback loop that generates laser operation at a specified passband wavelength of the Hi-Q wavelength filter 710.

[0047] The wavelength tuning controller 720 can control and / or tune a specified passband, and therefore can control and / or tune the laser wavelength of the laser device 300. For this purpose, the wavelength tuning controller 720 may include a heater for controlling the operating temperature of the Hi-Q filter 710, a current controller for controlling the current injected into the Hi-Q filter 720, and / or a voltage controller for controlling the voltage applied to the Hi-Q filter 720.

[0048] Figure 7B Another wavelength reference library 700B suitable for implementing wavelength reference library 360 is depicted. Specifically, wavelength reference library 700B may include a group or library of high-quality (Hi-Q) microring resonators 712 and a wavelength tuning controller 722. Each Hi-Q microring resonator 712 can resonate with a portion of light received from the input of wavelength reference library 700B that falls within a specified wavelength band of the corresponding Hi-Q microring resonator 712, and can transmit the light of the specified wavelength band to the output of wavelength reference library 700B. In this way, wavelength reference library 700B can provide a wavelength-selective feedback loop that generates laser operation at a specified wavelength band of the Hi-Q microring resonator 712. In other embodiments, wavelength reference library 360 may be implemented using resonant etalons, grating couplers, and / or other band-selective components instead of [other components]. Figure 7A and Figure 7B The Hi-Q wavelength filter 710 and the Hi-Q microring resonator 712, or as a supplement thereof.

[0049] In various embodiments, the multiplexer 310, demultiplexer 330, and / or wavelength reference library 360 can be implemented using undoped waveguide materials and / or waveguide materials different from ceramics. Therefore, the multiplexer 310, demultiplexer 330, and / or wavelength reference library 360 can be implemented using waveguide materials different from the doped ceramic material used to implement the doped ceramic waveguide 320.

[0050] Now for reference Figure 4Embodiments of an integrated doped ceramic waveguide laser device 400 are described according to various aspects of this disclosure. The laser device 400 may include a pump light input 402 and a WDM laser output 406. The pump light input 402 of the laser device 400 can receive pump light. Based on the received pump light, the laser device 400 can output WDM laser light via its WDM laser output 406.

[0051] Therefore, the laser device 400 may include a multiplexer 410, a doped ceramic waveguide 420, a demultiplexer 430, an optical signal combiner 440, a ring cavity 450, and a wavelength reference library 460. The multiplexer 410 may include a pump light input 412, a WDM optical signal input 414, and a combined optical signal output 416. The pump light input 412 of the multiplexer 410 can receive pump light from the pump light output 446 of the optical signal combiner 440. Furthermore, the WDM optical signal input 414 of the multiplexer 410 can receive WDM optical signals from the wavelength reference library 460. The multiplexer 410 can output a combined optical signal, including the pump light and the WDM optical signal, to the doped ceramic waveguide 420.

[0052] The doped ceramic waveguide 420 may include a waveguide input 422 and a waveguide output 424. The doped ceramic waveguide 420 can receive combined optical signals from the multiplexer 410 via its waveguide input 422. In addition, the doped ceramic waveguide 420 can guide the combined optical signals to its waveguide output 424 and the demultiplexer 430.

[0053] As the combined optical signal propagates along the doped ceramic waveguide 420, the pump light can excite the rare-earth ions in the waveguide to a higher energy state. When photons from the WDM optical signal encounter the excited rare-earth ions, the ions may undergo stimulated emission and return to a lower energy state. During this return, the rare-earth ions can release their energy as additional photons, which are in the same phase and direction as the WDM optical signal. In this way, as the pump light and the WDM optical signal propagate along the length of the doped ceramic waveguide 420, the pump light and its interaction with the rare-earth ions can amplify the WDM optical signal. For this purpose, the ceramic material of the waveguide 420 can be doped with rare-earth atoms, such as erbium (Er), praseodymium (Pr), holmium (Ho), Ba, Sr, Ca, Yb, etc.

[0054] The ceramic material used in the doped ceramic waveguide 420 can have a wide bandgap energy. For example, the bandgap energy of the doped ceramic waveguide 420 can be greater than or equal to 1.2 times the incident photon energy of the WDM optical signal or pump light. The ceramic material can also have a resistance greater than or equal to 1 ohm-cm, and the refractive index of the ceramic material can be greater than or equal to that of the cladding material (e.g., Figures 6A to 6H The refractive index of the cladding material (610, 630, 640) is 1.1 times that of the substrate ceramic material of the doped ceramic waveguide 220. Therefore, the matrix ceramic material of the doped ceramic waveguide 220 can use base materials such as SiC, AlN, AlN, and AlN2. x O y It is formed by ceramic matrix composites of materials such as Al2O3, BN, GaN, GaO, and LiNbO3, as well as dielectric materials such as SiN, SiNO, and glass.

[0055] Demultiplexer 430 may include a combined optical signal input 432, a pump light output 434, and a WDM laser output 436. Demultiplexer 430 can receive a combined optical signal including residual pump light, an amplified version of the WDM optical signal, and the WDM laser via its combined optical signal input 432. Demultiplexer 430 can demultiplex the residual pump light from the combined light and guide it to its pump light output 434 and the ring cavity 450. Similarly, demultiplexer 430 can demultiplex the WDM laser from the combined optical signal and guide it to its WDM laser output 436 and the WDM laser signal output 306 of the laser device 400. Furthermore, demultiplexer 430 can guide the amplified WDM optical signal to multiplexer 410 via its WDM optical signal output 438 and a wavelength reference library 460, which can be configured to... Figure 3 It is implemented in a similar way to the wavelength reference library 360.

[0056] The ring cavity 450 can receive residual pump light from the demultiplexer 430 and direct such residual pump light to the optical signal combiner 440. The optical signal combiner 440 may include a pump light input 442, a residual pump light input 444, and a pump light output 446. The pump light input 442 of the optical signal combiner 440 can receive pump light from the pump light input 402 of the laser device 400, and the residual pump light input 444 of the optical signal combiner 440 can receive residual pump light from the ring cavity 450. The optical signal combiner 440 can combine the received pump light and the residual pump light and direct the combined pump light to its pump light output 446 and the pump light input 412 of the multiplexer 410.

[0057] In various embodiments, the multiplexer 410, demultiplexer 430, optical signal combiner 440, ring cavity 450, and / or wavelength reference library 460 can be implemented using undoped waveguide materials and / or waveguide materials different from ceramics. Therefore, the multiplexer 410, demultiplexer 430, optical signal combiner 440, ring cavity 450, and / or wavelength reference library 460 can be implemented using waveguide materials different from the doped ceramic material used to implement the doped ceramic waveguide 220.

[0058] Now for reference Figure 5 Flowchart and Figures 6A to 6H The cross-section describes an optical structure fabricated with doped ceramic waveguides (such as, for example...). Figures 1 to 4 The process 500 (structure of the substrate) can be initiated at 510 by providing a substrate 600. The substrate 600 may include a top side 602, a bottom side 604, and one or more lateral sides 606 located between the top side 602 and the bottom side 604. The substrate 600 may include silicon, InP, GaAs, other semiconductor materials, glass, sapphire, ceramic materials, metals, etc. See, for example, [link to relevant documentation]. Figure 6A .

[0059] In step 520, process 500 can form a lower cladding layer 610 on the substrate 600. For example, see... Figure 6B Specifically, the lower cladding layer 610 may include a lower cladding layer top side 612, a lower cladding layer bottom side 614 of the contact substrate top side 602, and one or more lower cladding layer lateral sides 616 located between the lower cladding layer top side 612 and the lower cladding layer bottom side 614. The lower cladding layer 610 may include various dielectric materials, such as SiO2, SiN, SiNO, polymers, etc., which provide low optical loss and higher performance than corresponding waveguide core materials (such as...). Figure 6C The doped ceramic layer (620) has a lower refractive index.

[0060] After the lower cladding layer 610 is formed, at 530, a doped ceramic layer 620 can be formed on the lower cladding layer 610. For example, see Figure 6C As shown in the figure, the doped ceramic layer 620 may include a top side 622 of the ceramic layer, a bottom side 624 of the ceramic layer contacting the top side 612 of the lower cladding layer, and one or more lateral sides 626 of the ceramic layer located between the top side 622 and the bottom side 624. Specifically, the doped ceramic layer 620 may be doped with various rare earth dopants, such as erbium (Er), praseodymium (Pr), holmium (Ho), Ba, Sr, Ca, Yb, etc. As described above, such rare earth dopants can be excited by pump light and can impart optical gain to the WDM optical signal when the pump light and the WDM optical signal propagate through the doped ceramic layer 620.

[0061] To this end, process 500 can utilize plasma-assisted deposition of ceramics to co-dop and form a doped ceramic layer 620 with rare-earth dopants. Plasma-assisted deposition of the doped ceramic layer 620 can provide various advantages over conventional processes used to form and dop ceramic materials. Specifically, rare-earth dopants can be carried by plasma and deposited together with the matrix waveguide material (e.g., the ceramic material of the doped ceramic layer 620). Compared to conventional processes such as chemical vapor deposition (CVD), such plasma-assisted deposition can ensure the formation of a consistent and high-quality layer on diverse surfaces and at low temperatures. Such uniformity ensures that pump light irradiates the uniformly distributed rare-earth material layer at high density without rare-earth material aggregation, thereby allowing for high optical gain.

[0062] Furthermore, ion implantation processes can cause ion-induced damage in the resulting ceramic layer due to ion implantation. Plasma-assisted deposition avoids such ion-induced damage, resulting in a doped ceramic layer 620 with fewer optical defects. The high deposition temperatures of CVD can cause rare-earth dopants to diffuse and aggregate. Plasma-assisted deposition utilizes a lower deposition temperature process, thus avoiding the aggregation problems of conventional CVD processes. Such lower deposition temperatures also facilitate the deposition of wide-bandgap materials (e.g., dielectrics or ceramics) with co-doped rare-earth elements, and this can be achieved without introducing defects into previously formed cladding layers (such as the lower cladding 610).

[0063] At 540, process 500 can form a thin upper cladding layer 630 on the doped ceramic layer 620. For example, see... Figure 6D Specifically, the thin upper cladding 630 may include a top side 632 of the thin upper cladding, a bottom side 634 of the thin upper cladding contacting the top side 622 of the ceramic layer, and one or more lateral sides 636 of the thin upper cladding located between the top side 632 and the bottom side 634. Similar to the lower cladding 610, the thin upper cladding 630 may include various dielectric materials, such as SiO2, SiN, SiNO, polymers, etc., which provide low optical loss and better performance than corresponding waveguide core materials (such as 530 and...). Figure 6C The doped ceramic layer (620) has a lower refractive index.

[0064] At 550, process 500 can etch a thin upper cladding 630, a doped ceramic layer 620, and a lower cladding 610 to define or delineate the doped ceramic waveguide and / or other optical structures (such as...). Figures 1 to 4 (The optical structure). In various embodiments, this etching / definition of the doped ceramic layer 620 and / or cladding layers 610, 630 can be performed using dry etching and / or ion milling processes. See, for example, [link to documentation]. Figure 6E .

[0065] In process 560, process 500 can form a thick upper cladding layer 640 on the top side 632 of the thin upper cladding layer, the top side 602 of the substrate, and the exposed lateral sides 616, 626, 636 of the lower cladding layer 610, the doped ceramic layer 620, and the thin upper cladding layer 630. For example, see Figure 6F Specifically, the thick upper cladding 640 may include a top side 642 of the thick upper cladding, a bottom side 644 of the thick upper cladding connecting to the top side 602 of the contact substrate, and one or more lateral sides 646 of the thick upper cladding located between the top side 642 and the bottom side 644. Furthermore, one or more lateral sides 646 of the thick upper cladding may contact and cover the exposed lateral sides 616, 626, and 636 of the lower cladding 610, the doped ceramic layer 620, and the thin upper cladding 630. Similar to the thin upper cladding 630, the thick upper cladding 640 may include various dielectric materials, such as SiO2, SiN, SiNO, polymers, etc., which provide low optical loss and better performance than corresponding waveguide core materials (such as 530 and...). Figure 6C The doped ceramic layer (620) has a lower refractive index.

[0066] At 570, process 500 can etch a thick upper cladding 640 to define or delineate the cladding-doped ceramic waveguide and / or, for example, Figures 1 to 4 Other optical structures. Furthermore, such etching can define or delineate waveguides and / or other optical structures that do not utilize the doped ceramic layer 620. See, for example, [link to relevant documentation]. Figure 6G In various implementations, such etching / definition can be performed using dry etching and / or ion milling processes in a manner similar to etching at 550. However, in some cases, other etching processes, such as chemical etching, can be utilized.

[0067] Finally, process 500 can complete the formation of the corresponding optical structure at 580. Specifically, process 500 can form and define an additional layer 650 to form and interconnect waveguides, filters, multiplexers, demultiplexers, optical signal combiners, wavelength reference libraries, etc., of the corresponding optical structure. For example, see Figure 6H .

[0068] This disclosure includes references to certain examples; however, those skilled in the art will understand that various changes can be made and equivalents can be substituted without departing from the scope of this disclosure. Furthermore, modifications can be made to the disclosed examples without departing from the scope of this disclosure. For example, various embodiments of single-stage optical amplifiers have been disclosed. However, the features of such optical amplifiers can be extended to multi-stage amplifiers on a chip, or multiple single-amplifier chips can be cascaded to achieve high gain or optical output power. Therefore, this disclosure is not intended to be limited to the disclosed examples, but rather to include all examples falling within the scope of the appended claims.

Claims

1. An optical device, comprising: A multiplexer includes a pump light input for receiving pump light, a WDM optical signal input for receiving wavelength division multiplexed (WDM) optical signals, and a combined optical signal output. The multiplexer provides a combined optical signal to the combined optical signal output, the combined optical signal including the pump light received via the pump light input and the WDM optical signal received via the WDM optical signal input. as well as A ceramic waveguide includes a waveguide input terminal coupled to the combined optical signal output terminal of the multiplexer to receive the combined optical signal provided by the multiplexer; and The ceramic waveguide includes rare earth dopants, which impart optical gain to the WDM optical signal of the combined optical signal when the pump light and the WDM optical signal of the combined optical signal propagate along the ceramic waveguide.

2. The optical device according to claim 1, comprising: A filter is coupled to the waveguide output of the ceramic waveguide to receive residual pump light and the WDM optical signal; and The filter is configured to filter out the residual pump light from the WDM optical signal and provide the WDM optical signal to the WDM optical signal output terminal.

3. The optical device according to claim 1, comprising: An optical signal combiner includes a pump light input for receiving pump light, a residual pump light input for receiving residual pump light, and a pump light output coupled to the pump light input of the multiplexer, wherein the optical signal combiner is configured to provide the pump light to the pump light output of the optical signal combiner, comprising the pump light received via the pump light input of the optical signal combiner and the residual pump light received via the residual pump light input of the optical signal combiner; and A ring cavity is configured to guide the residual pump light from the waveguide output of the ceramic waveguide to the residual pump light input of the optical signal combiner.

4. The optical device according to claim 1, comprising: An optical signal combiner includes a pump light input for receiving pump light, a residual pump light input for receiving residual pump light, and a pump light output coupled to the pump light input of the multiplexer, wherein the optical signal combiner is configured to provide the pump light to the pump light output of the optical signal combiner, comprising the pump light received via the pump light input of the optical signal combiner and the residual pump light received via the residual pump light input of the optical signal combiner; and A demultiplexer, coupled to the waveguide output of the ceramic waveguide, is used to receive the residual pump light; and A ring cavity is disposed between the demultiplexer and the optical signal combiner; and The demultiplexer is configured to guide the residual pump light from the waveguide output to the residual pump light input of the optical signal combiner via the annular cavity.

5. The optical device according to claim 4, wherein, The demultiplexer is configured to guide the WDM optical signal received from the waveguide output to the WDM optical signal output.

6. The optical device according to claim 1, comprising: A demultiplexer is coupled to the waveguide output of the ceramic waveguide to receive the WDM optical signal; as well as A wavelength reference library is located between the multiplexer and the demultiplexer; and The demultiplexer is configured to guide the WDM optical signal from the waveguide output to the multiplexer via the wavelength reference library.

7. The optical device according to claim 6, wherein, The demultiplexer is configured to guide the WDM laser received from the waveguide output to the WDM laser output.

8. The optical device according to claim 6, comprising: An optical signal combiner includes a pump light input for receiving pump light, a residual pump light input for receiving residual pump light, and a pump light output coupled to the pump light input of the multiplexer, wherein the optical signal combiner is configured to provide the pump light to the pump light output of the optical signal combiner, comprising the pump light received via the pump light input of the optical signal combiner and the residual pump light received via the residual pump light input of the optical signal combiner; and A ring cavity is configured to guide the residual pump light from the waveguide output to the residual pump light input of the optical signal combiner.

9. The optical device according to claim 8, wherein, The demultiplexer is configured to guide the WDM laser received from the waveguide output to the WDM laser output.

10. A method of forming an optical device, the method comprising: A lower cladding layer is formed on the substrate; A doped ceramic layer is formed on the lower cladding using a plasma-assisted process, wherein the plasma-assisted process deposits ceramic material and co-dops the ceramic material with rare earth dopants; A first upper cladding layer is formed on the doped ceramic layer; and A portion of the first upper cladding and a portion of the doped ceramic layer are removed to form a doped ceramic waveguide.

11. The method of claim 10, comprising: A second upper cladding layer is formed on the first upper cladding layer and the doped ceramic waveguide; and A portion of the second upper cladding is removed to form at least a portion of the additional optical structure of the optical device.

12. The method according to claim 11, wherein: The additional optical structure includes a multiplexer comprising a pump light input for receiving pump light, a WDM optical signal input for receiving wavelength division multiplexed (WDM) optical signals, and a combined optical signal output. The multiplexer provides a combined optical signal to the combined optical signal output, the combined optical signal including the pump light received via the pump light input and the WDM optical signal received via the WDM optical signal input. The doped ceramic waveguide includes a waveguide input terminal, which is coupled to the combined optical signal output terminal of the multiplexer to receive the combined optical signal provided by the multiplexer. and When the pump light and the WDM optical signal of the combined optical signal propagate along the doped ceramic waveguide, the rare earth dopant of the doped ceramic waveguide imparts optical gain to the WDM optical signal of the combined optical signal.

13. The method according to claim 12, wherein: The additional optical structure includes a filter coupled to the waveguide output of the doped ceramic waveguide to receive residual pump light and the WDM optical signal; and The filter is configured to filter out the residual pump light from the WDM optical signal and provide the WDM optical signal to the WDM optical signal output.

14. The method according to claim 12, wherein: The additional optical structure includes an optical signal combiner and a ring cavity; The optical signal combiner includes a pump light input terminal for receiving pump light, a residual pump light input terminal for receiving residual pump light, and a pump light output terminal coupled to the pump light input terminal of the multiplexer. The optical signal combiner is configured to provide pump light to the pump light output of the optical signal combiner, including pump light received via the pump light input of the optical signal combiner and residual pump light received via the residual pump light input of the optical signal combiner. and The annular cavity is configured to guide the residual pump light from the waveguide output of the doped ceramic waveguide to the residual pump light input of the optical signal combiner.

15. The method according to claim 12, wherein: The additional optical structures include an optical signal combiner, a demultiplexer, and a ring cavity; The optical signal combiner includes a pump light input terminal for receiving pump light, a residual pump light input terminal for receiving residual pump light, and a pump light output terminal coupled to the pump light input terminal of the multiplexer. The optical signal combiner is configured to provide pump light to the pump light output of the optical signal combiner, including pump light received via the pump light input of the optical signal combiner and residual pump light received via the residual pump light input of the optical signal combiner. The demultiplexer is coupled to the waveguide output of the doped ceramic waveguide to receive the residual pump light; The demultiplexer is configured to guide the residual pump light from the waveguide output to the residual pump light input of the optical signal combiner via the annular cavity.

16. The method according to claim 15, wherein, The demultiplexer is configured to guide the WDM optical signal received from the waveguide output to the WDM optical signal output.

17. The method according to claim 12, wherein: The additional optical structures include a demultiplexer and a wavelength reference library; The demultiplexer is coupled to the waveguide output of the doped ceramic waveguide to receive the WDM optical signal; and The demultiplexer is configured to guide the WDM optical signal from the waveguide output to the multiplexer via the wavelength reference library.

18. The method according to claim 17, wherein, The demultiplexer is configured to guide the WDM laser received from the waveguide output to the WDM laser output.

19. The method of claim 17, wherein: The additional optical structure includes an optical signal combiner and a ring cavity; The optical signal combiner includes a pump light input terminal for receiving pump light, a residual pump light input terminal for receiving residual pump light, and a pump light output terminal coupled to the pump light input terminal of the multiplexer. The optical signal combiner is configured to provide pump light to the pump light output of the optical signal combiner, including pump light received via the pump light input of the optical signal combiner and residual pump light received via the residual pump light input of the optical signal combiner. and The annular cavity is configured to guide residual pump light from the waveguide output to the residual pump light input of the optical signal combiner.

20. The method according to claim 19, wherein, The demultiplexer is configured to guide the WDM laser received from the waveguide output to the WDM laser output.

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