1
|
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.
Collapse
|
2
|
Xiang C, Jin W, Terra O, Dong B, Wang H, Wu L, Guo J, Morin TJ, Hughes E, Peters J, Ji QX, Feshali A, Paniccia M, Vahala KJ, Bowers JE. 3D integration enables ultralow-noise isolator-free lasers in silicon photonics. Nature 2023; 620:78-85. [PMID: 37532812 PMCID: PMC10396957 DOI: 10.1038/s41586-023-06251-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 05/23/2023] [Indexed: 08/04/2023]
Abstract
Photonic integrated circuits are widely used in applications such as telecommunications and data-centre interconnects1-5. However, in optical systems such as microwave synthesizers6, optical gyroscopes7 and atomic clocks8, photonic integrated circuits are still considered inferior solutions despite their advantages in size, weight, power consumption and cost. Such high-precision and highly coherent applications favour ultralow-noise laser sources to be integrated with other photonic components in a compact and robustly aligned format-that is, on a single chip-for photonic integrated circuits to replace bulk optics and fibres. There are two major issues preventing the realization of such envisioned photonic integrated circuits: the high phase noise of semiconductor lasers and the difficulty of integrating optical isolators directly on-chip. Here we challenge this convention by leveraging three-dimensional integration that results in ultralow-noise lasers with isolator-free operation for silicon photonics. Through multiple monolithic and heterogeneous processing sequences, direct on-chip integration of III-V gain medium and ultralow-loss silicon nitride waveguides with optical loss around 0.5 decibels per metre are demonstrated. Consequently, the demonstrated photonic integrated circuit enters a regime that gives rise to ultralow-noise lasers and microwave synthesizers without the need for optical isolators, owing to the ultrahigh-quality-factor cavity. Such photonic integrated circuits also offer superior scalability for complex functionalities and volume production, as well as improved stability and reliability over time. The three-dimensional integration on ultralow-loss photonic integrated circuits thus marks a critical step towards complex systems and networks on silicon.
Collapse
Affiliation(s)
- Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
| | - Warren Jin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
- Anello Photonics, Santa Clara, CA, USA
| | - Osama Terra
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
- Primary Length and Laser Technology Lab, National Institute of Standards, Giza, Egypt
| | - Bozhang Dong
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Heming Wang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Lue Wu
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Theodore J Morin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Eamonn Hughes
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Jonathan Peters
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Qing-Xin Ji
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | | | | | - Kerry J Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, USA.
| |
Collapse
|
3
|
Guo J, McLemore CA, Xiang C, Lee D, Wu L, Jin W, Kelleher M, Jin N, Mason D, Chang L, Feshali A, Paniccia M, Rakich PT, Vahala KJ, Diddams SA, Quinlan F, Bowers JE. Chip-based laser with 1-hertz integrated linewidth. SCIENCE ADVANCES 2022; 8:eabp9006. [PMID: 36306350 PMCID: PMC9616488 DOI: 10.1126/sciadv.abp9006] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Lasers with hertz linewidths at time scales of seconds are critical for metrology, timekeeping, and manipulation of quantum systems. Such frequency stability relies on bulk-optic lasers and reference cavities, where increased size is leveraged to reduce noise but with the trade-off of cost, hand assembly, and limited applications. Alternatively, planar waveguide-based lasers enjoy complementary metal-oxide semiconductor scalability yet are fundamentally limited from achieving hertz linewidths by stochastic noise and thermal sensitivity. In this work, we demonstrate a laser system with a 1-s linewidth of 1.1 Hz and fractional frequency instability below 10-14 to 1 s. This low-noise performance leverages integrated lasers together with an 8-ml vacuum-gap cavity using microfabricated mirrors. All critical components are lithographically defined on planar substrates, holding potential for high-volume manufacturing. Consequently, this work provides an important advance toward compact lasers with hertz linewidths for portable optical clocks, radio frequency photonic oscillators, and related communication and navigation systems.
Collapse
Affiliation(s)
- Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Charles A. McLemore
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Dahyeon Lee
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - Lue Wu
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Warren Jin
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Megan Kelleher
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - Naijun Jin
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
| | - David Mason
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | | | | | - Peter T. Rakich
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
| | - Kerry J. Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Scott A. Diddams
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, 425 UCB, Boulder, CO 80309, USA
| | - Franklyn Quinlan
- National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, 440 UCB Boulder, CO 80309, USA
| | - John E. Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| |
Collapse
|
4
|
Optical characterization of deuterated silicon-rich nitride waveguides. Sci Rep 2022; 12:12697. [PMID: 35882882 PMCID: PMC9325772 DOI: 10.1038/s41598-022-16889-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/18/2022] [Indexed: 11/23/2022] Open
Abstract
Chemical vapor deposition-based growth techniques allow flexible design of complementary metal-oxide semiconductor (CMOS) compatible materials. Here, we report the deuterated silicon-rich nitride films grown using plasma-enhanced chemical vapor deposition. The linear and nonlinear properties of the films are characterized, and we experimentally confirm that the silicon-rich nitride films grown with SiD4 eliminates Si–H and N–H related absorption. The performance of identical waveguides for films grown with SiH4 and SiD4 are compared demonstrating a 2 dB/cm improvement in line with that observed in literature. Waveguides fabricated on the SRN:D film are further shown to possess a nonlinear parameter of 95 W−1 m−1, with the film exhibiting a linear and nonlinear refractive index of 2.46 and 9.8 \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\times$$\end{document}× 10–18 m2W−1 respectively.
Collapse
|
5
|
Platicon microcomb generation using laser self-injection locking. Nat Commun 2022; 13:1771. [PMID: 35365647 PMCID: PMC8975808 DOI: 10.1038/s41467-022-29431-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 02/25/2022] [Indexed: 11/24/2022] Open
Abstract
The past decade has witnessed major advances in the development and system-level applications of photonic integrated microcombs, that are coherent, broadband optical frequency combs with repetition rates in the millimeter-wave to terahertz domain. Most of these advances are based on harnessing of dissipative Kerr solitons (DKS) in microresonators with anomalous group velocity dispersion (GVD). However, microcombs can also be generated with normal GVD using localized structures that are referred to as dark pulses, switching waves or platicons. Compared with DKS microcombs that require specific designs and fabrication techniques for dispersion engineering, platicon microcombs can be readily built using CMOS-compatible platforms such as thin-film (i.e., thickness below 300 nm) silicon nitride with normal GVD. Here, we use laser self-injection locking to demonstrate a fully integrated platicon microcomb operating at a microwave K-band repetition rate. A distributed feedback (DFB) laser edge-coupled to a Si3N4 chip is self-injection-locked to a high-Q ( > 107) microresonator with high confinement waveguides, and directly excites platicons without sophisticated active control. We demonstrate multi-platicon states and switching, perform optical feedback phase study and characterize the phase noise of the K-band platicon repetition rate and the pump laser. Laser self-injection-locked platicons could facilitate the wide adoption of microcombs as a building block in photonic integrated circuits via commercial foundry service. ’Here the authors provide the demonstration of platicon comb generation in an integrated photonic chip using laser self-injection locking, They take advantage of platicons generation in normal GVD resonators, which significantly relaxes the material and geometry design restrictions
Collapse
|
6
|
Wu Z, Zhang Y, Zeng S, Li J, Xie Y, Chen Y, Yu S. Low-noise Kerr frequency comb generation with low temperature deuterated silicon nitride waveguides. OPTICS EXPRESS 2021; 29:29557-29566. [PMID: 34615064 DOI: 10.1364/oe.438436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
We report very low-loss deuterated silicon nitride (SiNx:D) micro-ring resonators fabricated by back-end CMOS compatible low-temperature plasma-enhanced chemical vapor deposition (PECVD) without annealing. Strong confinement micro-ring resonators with a quality factor of > 2 million are achieved, corresponding to a propagation loss in the 1460-1610 nm wavelength range of ∼ 0.17 dB/cm. We further report the generation of low-noise coherent Kerr microcomb states including different perfect soliton crystals (PSC) in PECVD SiNx:D micro-ring resonators. These results manifest the promising potential of the back-end CMOS compatible SiNx:D platform for linear and nonlinear photonic circuits that can be co-integrated with electronics.
Collapse
|
7
|
Xiang C, Liu J, Guo J, Chang L, Wang RN, Weng W, Peters J, Xie W, Zhang Z, Riemensberger J, Selvidge J, Kippenberg TJ, Bowers JE. Laser soliton microcombs heterogeneously integrated on silicon. Science 2021; 373:99-103. [PMID: 34210884 DOI: 10.1126/science.abh2076] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/20/2021] [Indexed: 12/22/2022]
Abstract
Silicon photonics enables wafer-scale integration of optical functionalities on chip. Silicon-based laser frequency combs can provide integrated sources of mutually coherent laser lines for terabit-per-second transceivers, parallel coherent light detection and ranging, or photonics-assisted signal processing. We report heterogeneously integrated laser soliton microcombs combining both indium phospide/silicon (InP/Si) semiconductor lasers and ultralow-loss silicon nitride (Si3N4) microresonators on a monolithic silicon substrate. Thousands of devices can be produced from a single wafer by using complementary metal-oxide-semiconductor-compatible techniques. With on-chip electrical control of the laser-microresonator relative optical phase, these devices can output single-soliton microcombs with a 100-gigahertz repetition rate. Furthermore, we observe laser frequency noise reduction due to self-injection locking of the InP/Si laser to the Si3N4 microresonator. Our approach provides a route for large-volume, low-cost manufacturing of narrow-linewidth, chip-based frequency combs for next-generation high-capacity transceivers, data centers, space and mobile platforms.
Collapse
Affiliation(s)
- Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Rui Ning Wang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Wenle Weng
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jonathan Peters
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Weiqiang Xie
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Zeyu Zhang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Johann Riemensberger
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jennifer Selvidge
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. .,Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| |
Collapse
|
8
|
Brian Sia JX, Li X, Wang W, Qiao Z, Guo X, Zhou J, Littlejohns CG, Liu C, Reed GT, Wang H. Sub-kHz linewidth, hybrid III-V/silicon wavelength-tunable laser diode operating at the application-rich 1647-1690 nm. OPTICS EXPRESS 2020; 28:25215-25224. [PMID: 32907047 DOI: 10.1364/oe.400666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
The wavelength region about of 1650 nm enables pervasive applications. Some instances include methane spectroscopy, free-space/fiber communications, LIDAR, gas sensing (i.e. C2H2, C2H4, C3H8), surgery and medical diagnostics. In this work, through the hybrid integration between an III-V optical amplifier and an extended, low-loss wavelength tunable silicon Vernier cavity, we report for the first time, a III-V/silicon hybrid wavelength-tunable laser covering the application-rich wavelength region of 1647-1690 nm. Room-temperature continuous wave operation is achieved with an output power of up to 31.1 mW, corresponding to a maximum side-mode suppression ratio of 46.01 dB. The laser is ultra-coherent, with an estimated linewidth of 0.7 kHz, characterized by integrating a 35 km-long recirculating fiber loop into the delayed self-heterodyne interferometer setup. The laser linewidth is amongst the lowest in hybrid/heterogeneous III-V/silicon lasers.
Collapse
|