| 1. |
- Gao, Yan, 1995, et al.
(författare)
-
Compact lithium niobate microring resonators in the ultrahigh Q/V regime
- 2023
-
Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 48:15, s. 3949-3952
-
Tidskriftsartikel (refereegranskat)abstract
- Lithium niobate (LN) is a promising material for future complex photonic-electronic circuits, with wide applications in such fields as communications, sensing, quantum optics, and computation. LN took a great stride toward compact photonic integrated circuits (PICs) with the development of partially etched LN on insulator (LNOI) waveguides. However, integration density is still limited for future highly compact PICs, owing to the partial etching nature of their waveguides. Here, we demonstrate a fully etched LN PIC platform, which, for the first time to our knowledge, simultaneously achieves ultralow propagation loss and compact circuit size. The tightly confined fully etched LN waveguides with smooth sidewalls allow us to bring the bending radius down to 20 μm (corresponding to 1 THz free spectral range). We have achieved compact high Q microring resonators with Q/V of 8.7 × 104 μm−3, almost one order of magnitude larger than previous demonstrations. The statistical mean propagation losses of our LN waveguides is 8.5 dB/m (corresponding to a mean Q factor of 4.9 × 106), even with a small bending radius of 40 μm. Our compact and ultralow-loss LN platform shows great potential in future miniaturized multifunctional integration systems. As complementary evidence to show the utility of our platform, we demonstrate soliton microcombs with an ultrahigh repetition rate of 500 GHz in LN.
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| 2. |
- Helgason, Òskar Bjarki, 1989, et al.
(författare)
-
Power-efficient soliton microcombs in anomalous-dispersion photonic molecules
- 2022
-
Ingår i: Optics InfoBase Conference Papers.
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate a microcomb with power conversion efficiency exceeding 50%. It originates from a single dissipative Kerr soliton circulating in an anomalous-dispersion microresonator whose pump resonance is shifted through linear coupling with an auxiliary cavity.
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| 3. |
- Helgason, Òskar Bjarki, 1989, et al.
(författare)
-
Surpassing the nonlinear conversion efficiency of soliton microcombs
- 2023
-
Ingår i: Nature Photonics. - 1749-4885 .- 1749-4893. ; 17:11, s. 992-999
-
Tidskriftsartikel (refereegranskat)abstract
- Laser frequency combs are enabling some of the most exciting scientific endeavours in the twenty-first century, ranging from the development of optical clocks to the calibration of the astronomical spectrographs used for discovering Earth-like exoplanets. Dissipative Kerr solitons generated in microresonators currently offer the prospect of attaining frequency combs in miniaturized systems by capitalizing on advances in photonic integration. Most of the applications based on soliton microcombs rely on tuning a continuous-wave laser into a longitudinal mode of a microresonator engineered to display anomalous dispersion. In this configuration, however, nonlinear physics precludes one from attaining dissipative Kerr solitons with high power conversion efficiency, with typical comb powers amounting to ~1% of the available laser power. Here we demonstrate that this fundamental limitation can be overcome by inducing a controllable frequency shift to a selected cavity resonance. Experimentally, we realize this shift using two linearly coupled anomalous-dispersion microresonators, resulting in a coherent dissipative Kerr soliton with a conversion efficiency exceeding 50% and excellent line spacing stability. We describe the soliton dynamics in this configuration and find vastly modified characteristics. By optimizing the microcomb power available on-chip, these results facilitate the practical implementation of a scalable integrated photonic architecture for energy-efficient applications.
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| 4. |
- Helgason, Òskar Bjarki, 1989, et al.
(författare)
-
Thermally stable initiation of dissipative Kerr solitons in photonic molecules
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023.
-
Konferensbidrag (refereegranskat)abstract
- Dissipative Kerr solitons (DKSs) have been heavily researched in the last decade. These are robust waveforms that are generated in a single anomalous-dispersion microresonator. Microcombs corresponding to a single DKS circulating in a microcavity have been demonstrated to be robust, enabling multiple different applications, such as spectroscopy and telecommunications [1]. However, the fact that the continuous-wave (CW) laser has to be operated far red-detuned from resonance leads to practical limitations. One such limitation is low conversion efficiency, due to much of the pump bypassing the cavity. A second limitation is a challenging DKS initiation, which is a consequence of the red side of resonance being thermally unstable in the majority of integration materials, often requiring time-sensitive control schemes [2], or auxiliary cooling lasers [3], to enable the initiation. In a recent work, we addressed the limited conversion efficiency by shifting the pumped resonance via an avoided mode-crossing enabled by linear coupling to an auxiliary cavity [4]. Here, we show that this coupled-cavity arrangement (a photonic molecule) allows the initiation process, including the final DKS state, to be operated with the CW laser consistently located on the blue side of the pumped resonance. This thermal stabilization leads to a robust initiation scheme, which is not readily available for DKSs in single anomalous-dispersion cavities.
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| 5. |
- Hu, Xiaonan, 1988, et al.
(författare)
-
Passive Si3N4 photonic integrated platform at 1μm for short-range optical interconnects
- 2019
-
Ingår i: 2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2019. - 2162-2701. ; Part F140-CLEO_Europe 2019
-
Konferensbidrag (refereegranskat)abstract
- With the increasing development of cloud services, a large number of high-speed optical interconnects are needed in large-scale datacenters. Future datacenters will require short-range links with multi-Tb/s interconnect capacity, i.e. more than an order of magnitude higher than what is available today with vertical-cavity surface-emission lasers (VCSELs) or silicon photonics. In addition, large-scale datacenters will require longer (> 1km) transmission links. Single-mode GaAs VCSELs today provide transmission speeds ∼ 100 Gb/s, close to their fundamental limit. The recent development of high-speed GaAs VCSELs at a slightly longer wavelength of opens a path forward for low-energy dissipation, high-speed, long-reach optical interconnects because the chromatic dispersion and attenuation in fibers are significantly reduced compared to shorter wavelengths [1]. In order to meet the future capacity prospects, we envision the use of multi-wavelength GaAs VCSEL arrays at 1 μm with advanced multi-fiber cables. This vision requires the use of a low-cost, low-loss passive integrated photonic platform for laser integration, multiplexing, and fiber interfacing, as sketched in Figure (a). Here, we present a silicon nitride (henceforth SiN) platform that can meet these requirements.
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| 6. |
- Hu, Xiaonan, 1988, et al.
(författare)
-
Si3N4 photonic integration platform at 1 µm for optical interconnects
- 2020
-
Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 28:9, s. 13019-13031
-
Tidskriftsartikel (refereegranskat)abstract
- Vertical-cavity surface-emitting lasers (VCSELs) are the predominant technology for high-speed short-range interconnects in data centers. Most short-range interconnects rely on GaAs-based multi-mode VCSELs and multi-mode fiber links operating at 850 nm. Recently, GaAs-based high-speed single-mode VCSELs at wavelengths > 1 µm have been demonstrated, which increases the interconnect reach using a single-mode fiber while maintaining low energy dissipation. If a suitable platform for passive wavelength- and space-multiplexing were developed in this wavelength range, this single-mode technology could deliver the multi-Tb/s interconnect capacity that will be required in future data centers. In this work, we show the first passive Si3N4 platform in the 1-µm band (1030-1075 nm) with an equivalent loss < 0.3 dB/cm, which is compatible with the system requirements of high-capacity interconnects. The waveguide structure is optimized to achieve simultaneously single-mode operation and low bending radius, and we demonstrate a wide range of high-performance building blocks, including arrayed waveguide gratings, Mach-Zehnder interferometers, splitters and low-loss fiber interfaces. This technology could be instrumental in scaling up the capacity and reducing the footprint of VCSEL-based optical interconnects and, thanks to the broad transparency in the near-infrared and compatibility with the Yb fiber amplifier window, enabling new applications in other domains as optical microscopy and nonlinear optics.
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| 7. |
- Lei, Fuchuan, 1987, et al.
(författare)
-
Hyperparametric Oscillation via Bound States in the Continuum
- 2023
-
Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 130:9
-
Tidskriftsartikel (refereegranskat)abstract
- Optical hyperparametric oscillation based on the third-order nonlinearity is one of the most significant mechanisms to generate coherent electromagnetic radiation and produce quantum states of light. Advances in dispersion-engineered high-Q microresonators allow for generating signal waves far from the pump and decrease the oscillation power threshold to submilliwatt levels. However, the pump-to-signal conversion efficiency and absolute signal power are low, fundamentally limited by parasitic mode competition and attainable cavity intrinsic Q to coupling Q ratio, i.e., Qi/Qc. Here, we use Friedrich-Wintgen bound states in the continuum (BICs) to overcome the physical challenges in an integrated microresonator-waveguide system. As a result, on-chip coherent hyperparametric oscillation is generated in BICs with unprecedented conversion efficiency and absolute signal power. This work not only opens a path to generate high-power and efficient continuous-wave electromagnetic radiation in Kerr nonlinear media but also enhances the understanding of a microresonator-waveguide system - an elementary unit of modern photonics.
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| 8. |
- Lei, Fuchuan, 1987, et al.
(författare)
-
Optical linewidth of soliton microcombs
- 2022
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding noise dynamics in frequency combs is crucial for applications. Here, the authors study the phase noise dynamics and the linewidth of soliton microcombs, revealing that some comb lines can be more quiet than the pump laser itself. Soliton microcombs provide a versatile platform for realizing fundamental studies and technological applications. To be utilized as frequency rulers for precision metrology, soliton microcombs must display broadband phase coherence, a parameter characterized by the optical phase or frequency noise of the comb lines and their corresponding optical linewidths. Here, we analyse the optical phase-noise dynamics in soliton microcombs generated in silicon nitride high-Q microresonators and show that, because of the Raman self-frequency shift or dispersive-wave recoil, the Lorentzian linewidth of some of the comb lines can, surprisingly, be narrower than that of the pump laser. This work elucidates information about the physical limits in phase coherence of soliton microcombs and illustrates a new strategy for the generation of spectrally coherent light on chip.
|
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| 9. |
- Lei, Fuchuan, 1987, et al.
(författare)
-
Power-efficient hyperparametric oscillation via bound states in the continuum
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023.
-
Konferensbidrag (refereegranskat)abstract
- Optical hyperparametric oscillation (h-OPO) emerges in a driven Kerr cavity because of modulation instability. Two pump photons are converted into a pair of two correlated photons at new wavelengths. For many realistic applications, efficient operation of h-OPO is required, especially at high-power regime. Currently, the pump-to-signal conversion efficiency is fundamentally limited mainly by two factors: parasitic mode competition [1] and attainable cavity intrinsic Q (Qi) to coupling Q (Qc) ratio [2].
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| 10. |
- O'Malley, Nathan P., et al.
(författare)
-
RF Stabilization of Vernier Dual-microcombs
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics, CLEO 2023.
-
Konferensbidrag (refereegranskat)abstract
- Leveraging the Vernier dual-comb method, we self-reference a THz octave-spanning microcomb with fCEO ~100 GHz - normally too high for typical detection equipment - and translate the stability of an RF reference to optical frequencies.
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| 11. |
- O'Malley, Nathan P., et al.
(författare)
-
Vernier Frequency Combs for Stabilization of RF/Optical Links
- 2022
-
Ingår i: Optics InfoBase Conference Papers. - 9781957171050
-
Konferensbidrag (refereegranskat)abstract
- We utilize the Vernier effect to partially stabilize a pair of high repetition rate, octave-spanning Kerr solitons in silicon nitride microrings fabricated on the same wafer.
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| 12. |
- O'Malley, Nathan P., et al.
(författare)
-
Vernier Microcombs for Future Miniature Yb + Clocks
- 2023
-
Ingår i: 2023 IEEE Photonics Conference, IPC 2023 - Proceedings.
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate an architecture for dualmicrocomb-based readout of an optical clock. Microcombs frequency-divide a compact narrow-linewidth laser, capable of being frequency-doubled to within a few GHz of a 171Yb+ clock transition, to an RF output.
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| 13. |
|
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| 14. |
|
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| 15. |
- Wu, Kaiyi, et al.
(författare)
-
Vernier microcombs for high-frequency carrier envelope offset and repetition rate detection
- 2023
-
Ingår i: Optica. - 2334-2536. ; 10:5, s. 626-633
-
Tidskriftsartikel (refereegranskat)abstract
- Recent developments in Kerr microcombs may pave the way to a future with fully stabilized ultralow size, weight, and power consumption (SWaP) frequency combs. Nevertheless, Kerr microcombs are still hindered by a band-width/repetition rate trade-off. That is, the octave bandwidth needed for self-referencing is typically realized only with similar to THz repetition rates beyond the range of standard commercial photodetectors. The carrier envelope offset fre-quency fCEO is often likewise too high for detection. Dual-comb techniques for the measurement of THz repetition rates have made exciting progress, but the fCEO detection problem remains largely unaddressed. In this work, utilizing a Vernier dual-comb configuration, we demonstrate simultaneous detection of the electronically divided similar to 900 GHz rep-etition rate and similar to 97 GHz carrier envelope offset frequency of an octave-spanning microcomb. This, in turn, could help usher optical atomic clocks, low-noise microwave generators, and optical frequency synthesizers into various real-world applications.Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
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| 16. |
- Ye, Zhichao, 1991, et al.
(författare)
-
25 GHz soliton microcombs in high-Q Si3N4 racetrack-shaped microresonators
- 2020
-
Ingår i: Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS. - 1092-8081. - 9781557528209
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate a 25 GHz single-soliton comb on a Si3N4 platform fabricated using a novel subtractive method. A long cavity is carefully designed to fit within the e-beam writing field while minimizing coupling to higher-order modes.
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| 17. |
- Ye, Zhichao, 1991, et al.
(författare)
-
Integrated, Ultra-Compact High-Q Silicon Nitride Microresonators for Low-Repetition-Rate Soliton Microcombs
- 2022
-
Ingår i: Laser and Photonics Reviews. - : Wiley. - 1863-8899 .- 1863-8880. ; 16:3
-
Tidskriftsartikel (refereegranskat)abstract
- Multiple applications of relevance in photonics, such as spectrally efficient coherent communications, microwave synthesis or the calibration of astronomical spectrographs, would benefit from soliton microcombs operating at repetition rates <50GHz. However, attaining soliton microcombs with low repetition rates using photonic integration technologies represents a formidable challenge. Expanding the cavity volume results in a drop of intracavity intensity that can only be offset by an encompassing rise in quality factor. In addition, reducing the footprint of the microresonator on an integrated circuit requires race-track designs that typically result into modal coupling losses and disruptions into the dispersion, preventing the generation of the dissipative single soliton state. Here, we report the generation of sub-50GHz soliton microcombs in dispersion-engineered silicon nitride microresonators. In contrast to other approaches, the authors' devices feature an optimized racetrack design that minimizes the coupling to higher-order modes and reduces the footprint size by an order of magnitude to approximate to 1mm(2). The statistical intrinsic Q reaches 19 million, and soliton microcombs at 20.5 and 14.0 GHz repetition rates are successfully generated. Importantly, the fabrication process is entirely subtractive, meaning that the devices can be directly patterned on the silicon nitride film.
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| 18. |
- Alam, A. S., et al.
(författare)
-
LiNbO3/Si3N4-Bilayer Vertical Coupler for Integrated Photonics
- 2020
-
Ingår i: Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS. - 1092-8081. ; 2020-May
-
Konferensbidrag (refereegranskat)abstract
- The design of a LiNbO3/Si3N4-bilayer vertical coupler is proposed based on adiabatic transition from a thick-Si3N4 strip waveguide to a LiNbO3/thin-Si3N4 striploaded hybrid waveguide having a gross coupling loss of ∼0.08 dB.
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| 19. |
- Caut, Alexander, 1994, et al.
(författare)
-
Channel Scalability of Silicon Nitride (De-)multiplexers for Optical Interconnects at 1 μm
- 2024
-
Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 42:1, s. 276-286
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an investigation of the channel scalability of silicon nitride (Si3N4)-based (de-)multiplexers in the 1-μm band (1015-1055 nm). We discuss 4-, 8- and 16-channel demultiplexers based on arrayed waveguide gratings (AWGs) and cascaded Mach-Zehnder interferometers (MZIs), with corresponding channel spacings of 8, 4 and 2 nm. Gaussian and flat-top response devices are considered for both technologies and we analyze the insertion loss, temperature sensitivity, response flatness, footprint and crosstalk (XT). We study the impact of the number of channels on the insertion loss and XT level. In the experimental part, we demonstrate a 4-channel Gaussian AWG. We also demonstrate 4-channel Gaussian and flat-top cascaded MZIs, based on multimode interferometers (MMIs) and directional couplers (DCs). The AWG is attractive due to its small footprint but its high manufacturing complexity makes the device more prone to fabrication defects, which can lead to higher loss and higher XT. For the Gaussian AWG and MZI, the XT level is approximately the same and increases with the number of channels from -28 to -23 dB at 4 and 16 channels respectively. The flat-top MZI has no extra-loss with respect to the flat-top AWG and has a better tolerance to high temperature operations. However, due to wavelength sensitive DCs, the XT of the flat-top MZI is higher than that of the flat-top AWG except for a 16-channel system.
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| 20. |
- Gao, Yan, 1995, et al.
(författare)
-
Low-loss compact lithium niobate photonic integrated circuits
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023.
-
Konferensbidrag (refereegranskat)abstract
- Lithium niobate (LN) is a promising material among integrated photonics, with applications like high-speed EO modulators, frequency combs, frequency converters, and photon-pair sources [1]. Increasing the system complexity of LN integrated circuits requires large-scale arrays of photonic components [2]. Therefore, an ideal integrated LN waveguide platform should allow dense integration, low propagation losses, and exhibit low fabrication complexity.
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| 21. |
- Girardi, Marcello, 1991, et al.
(författare)
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3D Integration of Microcombs
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023.
-
Konferensbidrag (refereegranskat)abstract
- Microcombs based on silicon nitride are a promising technology in applications such as sensing, metrology and telecommunication [1]. These applications often require to combine a nonlinear waveguide with a linear integrated processor on the same chip to perform functionalities such as splitting, demultiplexing, and optical buffering. However, there is a fundamental performance tradeoff between linear and nonlinear waveguides. For microcomb generation, thick waveguide cores are necessary to achieve the desired anomalous dispersion, while for linear operation a thin core improves the loss of a single mode (SM) waveguide [2]. The dissimilar requirements in waveguide thickness brings challenges for planar integrated technologies. Here, we propose and demonstrate wafer-level three-dimensional integration of microcombs using two different Si3N4 core thicknesses: a thick core featuring dispersion-engineered microcombs and a thinner core for linear processing (see Fig. 1a). This technology breaks off the fundamental tradeoff between loss and confinement in thick waveguides and opens the door to combine high-performance microcombs with ultra-low-loss silicon nitride waveguide technology [3]. We demonstrate this approach by efficiently coupling a microcomb between two layers of Si3N4 and demultiplexing a few lines with an arrayed waveguide grating (AWG) (Fig 1b).
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| 22. |
- Girardi, Marcello, 1991, et al.
(författare)
-
Multilayer integration in silicon nitride: decoupling linear and nonlinear functionalities for ultralow loss photonic integrated systems
- 2023
-
Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 31:19, s. 31435-31446
-
Tidskriftsartikel (refereegranskat)abstract
- Silicon nitride is an excellent material platform for its extremely low loss in a large wavelength range, which makes it ideal for the linear processing of optical signals on a chip. Moreover, the Kerr nonlinearity and the lack of two-photon absorption in the near infrared enable efficient nonlinear optics, e.g., frequency comb generation. However, linear and nonlinear operations require distinct engineering of the waveguide core geometry, resulting in a tradeoff between optical loss and single-mode behavior, which hinders the development of high-performance, ultralow-loss linear processing blocks on a single layer. Here, we demonstrate a dual-layer photonic integration approach with two silicon-nitride platforms exhibiting ultralow optical losses, i.e., a few dB/m, and individually optimized to perform either nonlinear or linear processing tasks. We demonstrate the functionality of this approach by integrating a power-efficient microcomb with an arrayed waveguide grating demultiplexer to filter a few frequency comb lines in the same monolithically integrated chip. This approach can significantly improve the integration of linear and nonlinear optical elements on a chip and opens the way to the development of fully integrated processing of Kerr nonlinear sources.
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| 23. |
- Girardi, Marcello, 1991, et al.
(författare)
-
Performance tradeoffs in low-loss Si3N4 waveguides for linear and nonlinear applications
- 2022
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We experimentally analyze tradeoffs in terms of waveguide losses, dispersion engineering and single-mode behaviour for different waveguide geometries. Our results suggests that photonic integrated circuits relying on nonlinear waveguides benefit from including a dedicated waveguide geometry via multi-layer integration to yield a seven-fold improvement in terms of loss.
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| 24. |
- Girardi, Marcello, 1991
(författare)
-
Wafer-level processing of ultralow-loss Si3N4
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Photonic integrated circuits (PICs) are devices fabricated on a planar wafer that allow light generation, processing, and detection. Photonic integration brings important advantages for scaling up the complexity and functionality of photonic systems and facilitates their mass deployment in areas where large volumes and compact solutions are needed, e.g., optical interconnects. Among the material platforms available, silicon nitride (Si3N4) displays excellent optical properties such as broadband transparency, moderately high refractive index, and relatively strong nonlinearities. Indeed, Si3N4 integrated waveguides display ultralow-loss (few decibels per meter), which enables efficient light processing and nonlinear optics. Moreover, Si3N4 is compatible with standard complementary metal oxide semiconductor (CMOS) processing techniques, which facilitates the manufacture scalability required by mass deployment of PICs. However, the selection of a single photonic platform sets limitations to the device functionalities due to the intrinsic properties of the material and the fundamental limitation of optical waveguiding. Multilayer integration of different platforms can overcome the limitations encountered in a singleplatform PIC. This thesis presents the development of advanced techniques for the waferlevel manufacturing of ultralow-loss Si3N4 devices and approaches to enable their interface with active components like modulators and chip-scale comb sources (microcombs). The investigation covers the tailoring of a waveguide to the functionality required, the wafer-scale manufacturing of Si3N4, and how to overcome the limitations of a single platform on a wafer. These studies enable high-yield fabrication of microcombs, the integration of two Si3N4 platforms on the same wafer, and a strategy to efficiently couple to an integrated LiNbO3 layer to expand the chip functionality and scale up the complexity of the PIC.
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| 25. |
- Rebolledo Salgado, Israel, 1992, et al.
(författare)
-
Active Feedback Stabilization of Super-efficient Microcombs
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). - : Institute of Electrical and Electronics Engineers (IEEE). - 2833-1052. - 9798350345995
-
Konferensbidrag (refereegranskat)abstract
- We report the long-term operation of a super-efficient microcomb. We use the soliton power to maintain a fixed pump detuning. The microcomb operates over 25 hours using a thermal control in a packaged module.
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| 26. |
- Rebolledo Salgado, Israel, 1992, et al.
(författare)
-
Active feedback stabilization of super-efficient microcombs in photonic molecules
- 2024
-
Ingår i: Optics Letters. - : Optica Publishing Group (formerly OSA). - 0146-9592 .- 1539-4794. ; 49:9, s. 2325-2328
-
Tidskriftsartikel (refereegranskat)abstract
- Dissipative Kerr soliton (DKS) frequency combs, when generated within coupled cavities, exhibit exceptional performance concerning controlled initiation and power conversion efficiency. Nevertheless, to fully exploit these enhanced capabilities, it is necessary to maintain the frequency comb in a low-noise state over an extended duration. In this study, we demonstrate the control and stabilization of super-efficient microcombs in a photonic molecule. Our findings demonstrate that there is a direct relation between effective detuning and soliton power, allowing the latter to be used as a setpoint in a feedback control loop. Employing this method, we achieve the stabilization of a highly efficient microcomb indefinitely, paving the way for its practical deployment in optical communications and dual-comb spectroscopy applications.
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| 27. |
- Rebolledo Salgado, Israel, 1992, et al.
(författare)
-
Thermal-Controlled Scanning of a Bright Soliton in a Photonic Molecule
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023.
-
Konferensbidrag (refereegranskat)abstract
- Over the last few years, dissipative Kerr solitons (DKS) in microresonators have boosted the development of chip-scale frequency comb sources (microcombs) in a variety of applications, from coherent communications to ultrafast distance ranging [1]. However, the intrinsic large free spectral range (FSR) of microcombs (within the gigahertz regime) is still a drawback for applications such as molecular spectroscopy, in which the comb line spacing dictates the spectral sampling resolution. Overcoming spectral sparsity by scanning the comb modes across a full FSR is challenging for a DKS microcomb, since the soliton operation must be kept while the pump laser is continuously swept. So far, it has been accomplished for a single microresonator by combining a feedback control loop with the thermal tuning of the cavity resonances by means of a microheater [2]. Recently, the use of two linearly coupled cavities (a photonic molecule) has shown to be a promising alternative to generate soliton microcombs with high conversion efficiency and uniform power distribution [3]. In this contribution, we address the challenge of scanning the soliton comb modes of a photonic molecule by thermal tuning. Specifically, we implement a scheme to scan a bright soliton over 60 GHz by tuning simultaneously the pump laser and the resonances of two coupled cavities.
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| 28. |
- Twayana, Krishna Sundar, 1986, et al.
(författare)
-
Multi-Heterodyne Differential Phase Measurement of Microcombs
- 2023
-
Ingår i: 2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). - 9798350345995 - 9798350345995
-
Konferensbidrag (refereegranskat)abstract
- Microcombs have been an intense area of research in frequency synthesis and metrology over the past decade. The measurement of amplitude and phase of microcombs provides unique insight into the nonlinear cavity dynamics. Different techniques have been reported to this aim, including iterative pulse shaping [1], dual-comb interferometry [2] and lately stepped-laser interferometry [3], resulting in unprecedented sensitivity and bandwidth. Here, we report a dramatic simplification of the latter setup by using another microcomb instead of a stepped tunable laser. This results into the acquisition of complex spectra in a single-scan without requiring additional optical components and high-end detection units.
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| 29. |
- Van Der Zon, Louw Roel, et al.
(författare)
-
Compact 8-channel Loop-back AWG based Integrated Comb Processor
- 2021
-
Ingår i: IEEE International Conference on Group IV Photonics GFP. - 1949-2081. ; 2021-December
-
Konferensbidrag (refereegranskat)abstract
- We present an 8-channel integrated comb source spectral processor based on an arrayed-waveguide grating with unconventional mounting, for improved aberration and sidelobes, in loop-back configuration. The spectral processor is fabricated in a silicon nitride platform and has a 100 GHz channel spacing.
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| 30. |
- Zhao, Ping, 1986, et al.
(författare)
-
0.9-dB/m Single-Mode Silicon Nitride Nonlinear Integrated Waveguides for Continuous-Wave Wavelength Conversion
- 2023
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Ingår i: 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023.
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Konferensbidrag (refereegranskat)abstract
- We present efficient wavelength conversion with an over-150-nm bandwidth, using single-mode Si3N4 Kerr integrated waveguides with record-low losses of l0.9pm 0.2dB/m, This enables a first-time 100-Gbps-single-channel all-optical L-to-S-band translation without amplifying signal/idler-waves for χ(3) waveguides.
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