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Geng Z, Cheng W, Yan Z, Yi Q, Liu Z, You M, Yu X, Wu P, Ding N, Tang X, Wang M, Shen L, Zhao Q. Low-loss tantalum pentoxide photonics with a CMOS-compatible process. OPTICS EXPRESS 2024; 32:12291-12302. [PMID: 38571056 DOI: 10.1364/oe.518545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/04/2024] [Indexed: 04/05/2024]
Abstract
We report a Ta2O5 photonic platform with a propagation loss of 0.49 dB/cm at 1550 nm, of 0.86 dB/cm at 780 nm, and of 3.76 dB/cm at 2000 nm. The thermal bistability measurement is conducted in the entire C-band for the first time to reveal the absorption loss of Ta2O5 waveguides, offering guidelines for further reduction of the waveguide loss. We also characterize the Ta2O5 waveguide temperature response, which shows favorable thermal stability. The fabrication process temperature is below 350°C, which is friendly to integration with active optoelectronic components.
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Lomonte E, Stappers M, Krämer L, Pernice WHP, Lenzini F. Scalable and efficient grating couplers on low-index photonic platforms enabled by cryogenic deep silicon etching. Sci Rep 2024; 14:4256. [PMID: 38383577 PMCID: PMC10881461 DOI: 10.1038/s41598-024-53975-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 02/07/2024] [Indexed: 02/23/2024] Open
Abstract
Efficient fiber-to-chip couplers for multi-port access to photonic integrated circuits are paramount for a broad class of applications, ranging, e.g., from telecommunication to photonic computing and quantum technologies. Grating-based approaches are often desirable for providing out-of-plane access to the photonic circuits. However, on photonic platforms characterized by a refractive index ≃ 2 at telecom wavelength, such as silicon nitride or thin-film lithium niobate, the limited scattering strength has thus far hindered the achievement of coupling efficiencies comparable to the ones attainable in silicon photonics. Here we present a flexible strategy for the realization of highly efficient grating couplers on such low-index photonic platforms. To simultaneously reach a high scattering efficiency and a near-unitary modal overlap with optical fibers, we make use of self-imaging gratings designed with a negative diffraction angle. To ensure high directionality of the diffracted light, we take advantage of a metal back-reflector patterned underneath the grating structure by cryogenic deep reactive ion etching of the silicon handle. Using silicon nitride as a testbed material, we experimentally demonstrate coupling efficiency up to - 0.55 dB in the telecom C-band with high chip-scale device yield.
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Affiliation(s)
- Emma Lomonte
- Institute of Physics, University of Münster, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- CeNTech-Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
- SoN-Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany
| | - Maik Stappers
- Institute of Physics, University of Münster, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- CeNTech-Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
- SoN-Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany
| | - Linus Krämer
- Institute of Physics, University of Münster, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
- CeNTech-Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany
- SoN-Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany
- Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Wolfram H P Pernice
- Institute of Physics, University of Münster, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany.
- CeNTech-Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany.
- SoN-Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany.
- Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.
| | - Francesco Lenzini
- Institute of Physics, University of Münster, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany.
- CeNTech-Center for Nanotechnology, Heisenbergstraße 11, 48149, Münster, Germany.
- SoN-Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany.
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Rasmus Bankwitz J, Wolff MA, Abazi AS, Piel PM, Jin L, Pernice WHP, Wurstbauer U, Schuck C. High-quality factor Ta 2O 5-on-insulator resonators with ultimate thermal stability. OPTICS LETTERS 2023; 48:5783-5786. [PMID: 37910758 DOI: 10.1364/ol.499726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/06/2023] [Indexed: 11/03/2023]
Abstract
Experiments in photonics, laser optics, and quantum technology require low-loss, thermal, and mechanical stability. While photonic integrated circuits on monolithic chips achieve interferometric stability, important nanophotonic material systems suffer from propagation loss, thermal drift, and noise that prevent, for example, precise frequency stabilization of resonators. Here we show that tantalum pentoxide (Ta2O5) on insulator micro-ring resonators combine quality factors beyond 1.8 Mio with vanishing temperature-dependent wavelength shift in a relevant 70 K to 90 K temperature range. Our Ta2O5-on-SiO2 devices will thus enable athermal operation at liquid nitrogen temperatures, paving the way for ultra-stable low-cost resonators, as desired for wavelength division multiplexing, on chip frequency stabilization and low-noise optical frequency comb generation.
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Timmerkamp M, Lüpken NM, Adrian Abazi S, Rasmus Bankwitz J, Schuck C, Fallnich C. Toward integrated tantalum pentoxide optical parametric oscillators. OPTICS LETTERS 2023; 48:4621-4624. [PMID: 37656570 DOI: 10.1364/ol.496990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/13/2023] [Indexed: 09/03/2023]
Abstract
We present a hybrid waveguide-fiber optical parametric oscillator (OPO) exploiting degenerate four-wave mixing in tantalum pentoxide. The OPO, pumped with ultrashort pulses at 1.55 µm wavelength, generated tunable idler pulses with up to 4.1 pJ energy tunable center wavelength between 1.63 µm and 1.68 µm. An upper bound for the total tolerable cavity loss of 32 dB was found, rendering a chip-integrated OPO feasible as a compact and robust light source.
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Sirleto L, Righini GC. An Introduction to Nonlinear Integrated Photonics Devices: Nonlinear Effects and Materials. MICROMACHINES 2023; 14:604. [PMID: 36985011 PMCID: PMC10058895 DOI: 10.3390/mi14030604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/24/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
The combination of integrated optics technologies with nonlinear photonics, which has led to the growth of nonlinear integrated photonics, has also opened the way to groundbreaking new devices and applications. Here we introduce the main physical processes involved in nonlinear photonics applications, and we discuss the fundaments of this research area, starting from traditional second-order and third-order phenomena and going to ultrafast phenomena. The applications, on the other hand, have been made possible by the availability of suitable materials, with high nonlinear coefficients, and/or by the design of guided-wave structures, which can enhance the material's nonlinear properties. A summary of the most common nonlinear materials is presented, together with a discussion of the innovative ones. The discussion of fabrication processes and integration platforms is the subject of a companion article, also submitted for publication in this journal. There, several examples of nonlinear photonic integrated devices to be employed in optical communications, all-optical signal processing and computing, or quantum optics are shown, too. We aimed at offering a broad overview, even if, certainly, not exhaustive. We hope that the overall work could provide guidance for those who are newcomers to this field and some hints to the interested researchers for a more detailed investigation of the present and future development of this hot and rapidly growing field.
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Affiliation(s)
- Luigi Sirleto
- National Research Council (CNR), Institute of Applied Sciences and Intelligent Systems (ISASI), Via Pietro Castellino 111, 80131 Napoli, Italy
| | - Giancarlo C. Righini
- National Research Council (CNR), Institute of Applied Physics (IFAC) “Nello Carrara”, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
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Timmerkamp M, Lüpken NM, Adrian Abazi S, Rasmus Bankwitz J, Schuck C, Fallnich C. Synchronously Pumped Tantalum Pentoxide Waveguide-based Optical Parametric Oscillator. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202226702024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Jean P, Douaud A, Toubou Bah S, LaRochelle S, Messaddeq Y, Shi W. Silicon-coupled tantalum pentoxide microresonators with broadband low thermo-optic coefficient. OPTICS LETTERS 2021; 46:3813-3816. [PMID: 34329288 DOI: 10.1364/ol.430417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Stable microresonators are important integrated photonics components but are difficult to achieve on silicon-on-insulator due to silicon intrinsic properties. In this work, we demonstrate broadband thermally stable tantalum pentoxide microresonators directly coupled to silicon waveguides using a micro-trench co-integration method. The method combines in-foundry silicon processing with a single step backend thin-film deposition. The passive response of the microresonator and its thermal behavior are investigated. We show that the microresonator can operate in the overcoupled regime as well as near the critical coupling point, boasting an extinction ratio over 25 dB with no higher-order mode excitation. The temperature dependent wavelength shift is measured to be as low as 8.9 pm/K and remains below 10 pm/K over a 120 nm bandwidth.
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Grottke T, Hartmann W, Schuck C, Pernice WHP. Optoelectromechanical phase shifter with low insertion loss and a 13π tuning range. OPTICS EXPRESS 2021; 29:5525-5537. [PMID: 33726088 DOI: 10.1364/oe.413202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
We present an on-chip optoectromechanical phase shifter with low insertion loss and low half-wave voltage using a silicon nitride platform. The device is based on a slot waveguide in which the electrostatic displacement of mechanical structures results in a change of the effective refractive index. We achieve insertion loss below 0.5 dB at a wavelength of 1550 nm in a Mach-Zehnder Interferometer with an extinction ratio of 31 dB. With a phase tuning length of 210 µm, we demonstrate a half-wave voltage of Vπ = 2.0 V and a 2π phase shift at V2π = 2.7 V. We measure phase shifts up to 13.3 π at 17 V. Our devices can be operated in the MHz range and allow for the generation of sub-µs pulses.
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Schrinner PPJ, Olthaus J, Reiter DE, Schuck C. Integration of Diamond-Based Quantum Emitters with Nanophotonic Circuits. NANO LETTERS 2020; 20:8170-8177. [PMID: 33136413 DOI: 10.1021/acs.nanolett.0c03262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nanophotonics provides a promising approach to advance quantum technology by replicating fundamental building blocks of nanoscale quantum optic systems in large numbers with high reproducibility on monolithic chips. While photonic integrated circuit components and single-photon detectors offer attractive performance on silicon chips, the large-scale integration of individually accessible quantum emitters has remained a challenge. Here, we demonstrate simultaneous optical access to several integrated solid-state spin systems with Purcell-enhanced coupling of single photons with high modal purity from lithographically positioned nitrogen vacancy centers into photonic integrated circuits. Photonic crystal cavities embedded in networks of tantalum pentoxide-on-insulator waveguides provide efficient interfaces to quantum emitters that allow us to optically detect magnetic resonances (ODMR) as desired in quantum sensing. Nanophotonic networks that provide configurable optical interfaces to nanoscale quantum emitters via many independent channels will allow for novel functionality in photonic quantum information processors and quantum sensing schemes.
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Affiliation(s)
- Philip P J Schrinner
- Institute of Physics, University of Münster, 48149 Münster, Germany
- Center for NanoTechnology - CeNTech, 48149 Münster, Germany
- Center for Soft Nanoscience - SoN, 48149 Münster, Germany
| | - Jan Olthaus
- Institut für Festkörpertheorie, University of Münster, 48149 Münster, Germany
| | - Doris E Reiter
- Institut für Festkörpertheorie, University of Münster, 48149 Münster, Germany
| | - Carsten Schuck
- Institute of Physics, University of Münster, 48149 Münster, Germany
- Center for NanoTechnology - CeNTech, 48149 Münster, Germany
- Center for Soft Nanoscience - SoN, 48149 Münster, Germany
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Wolff MA, Vogel S, Splitthoff L, Schuck C. Superconducting nanowire single-photon detectors integrated with tantalum pentoxide waveguides. Sci Rep 2020; 10:17170. [PMID: 33051576 PMCID: PMC7555505 DOI: 10.1038/s41598-020-74426-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/30/2020] [Indexed: 11/09/2022] Open
Abstract
Photonic integrated circuits hold great potential for realizing quantum technology. Efficient single-photon detectors are an essential constituent of any such quantum photonic implementation. In this regard waveguide-integrated superconducting nanowire single-photon detectors are an ideal match for achieving advanced photon counting capabilities in photonic integrated circuits. However, currently considered material systems do not readily satisfy the demands of next generation nanophotonic quantum technology platforms with integrated single-photon detectors, in terms of refractive-index contrast, band gap, optical nonlinearity, thermo-optic stability and fast single-photon counting with high signal-to-noise ratio. Here we show that such comprehensive functionality can be realized by integrating niobium titanium nitride superconducting nanowire single-photon detectors with tantalum pentoxide waveguides. We demonstrate state-of-the-art detector performance in this novel material system, including devices showing 75% on-chip detection efficiency at tens of dark counts per second, detector decay times below 1 ns and sub-30 ps timing accuracy for telecommunication wavelengths photons at 1550 nm. Notably, we realize saturation of the internal detection efficiency over a previously unattained bias current range for waveguide-integrated niobium titanium nitride superconducting nanowire single-photon detectors. Our work enables the full set of high-performance single-photon detection capabilities on the emerging tantalum pentoxide-on-insulator platform for future applications in integrated quantum photonics.
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Affiliation(s)
- Martin A Wolff
- Institute of Physics, University of Münster, Wilhelm-Klemm-Str. 10, 48149, Münster, Germany
- CeNTech - Center for Nanotechnology, Heisenbergstr. 11, 48149, Münster, Germany
- SoN - Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany
| | - Simon Vogel
- Institute of Physics, University of Münster, Wilhelm-Klemm-Str. 10, 48149, Münster, Germany
- CeNTech - Center for Nanotechnology, Heisenbergstr. 11, 48149, Münster, Germany
- SoN - Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany
| | - Lukas Splitthoff
- Institute of Physics, University of Münster, Wilhelm-Klemm-Str. 10, 48149, Münster, Germany
- CeNTech - Center for Nanotechnology, Heisenbergstr. 11, 48149, Münster, Germany
- SoN - Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany
| | - Carsten Schuck
- Institute of Physics, University of Münster, Wilhelm-Klemm-Str. 10, 48149, Münster, Germany.
- CeNTech - Center for Nanotechnology, Heisenbergstr. 11, 48149, Münster, Germany.
- SoN - Center for Soft Nanoscience, Busso-Peus-Straße 10, 48149, Münster, Germany.
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