TFLN Devices

Ultra-efficient frequency conversion in quasi-phase-matched lithium niobate microrings

We demonstrate quasi-phase-matched frequency conversion in a chip-integrated lithium niobate microring resonator, whose normalized efficiency reaches 230,000%/W or 10^−6 per single photon.

https://opg.optica.org/optica/fulltext.cfm?uri=optica-6-9-1244&id=420689

JY Chen, ZH Ma, YM Sua, Z Li, C Tang, YP Huang


Ultrabright Quantum Photon Sources on Chip

Quantum photon sources of high rate, brightness, and purity are increasingly desirable as quantum information systems are quickly scaled up and applied to many fields. Using a periodically poled lithium niobate microresonator on chip, we demonstrate photon-pair generation at high rates of 8.5 and 36.3 MHz using only 3.4 and 13.4 μ W pump power, respectively, marking orders of magnitude improvement over the state of the art, across all material platforms. These results constitute the first direct measurement of the device’s giant single photon nonlinearity. The measured coincidence to accidental ratio is well above 100 at those high rates and reaches 14 682±4427 at a lower pump power. The same chip enables heralded single-photon generation at tens of megahertz rates, each with low autocorrelation g H (2)(0)= 0.008 and 0.097 for the microwatt pumps, which marks a new milestone. Such distinct …

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.263602

Z Ma, JY Chen, Z Li, C Tang, YM Sua, H Fan, YP Huang


Efficient parametric frequency conversion in lithium niobate nanophotonic chips

Chip-integrated nonlinear photonics holds the key for advanced optical information processing with superior performance and novel functionalities. Here, we present an optimally mode-matched, periodically poled lithium niobate nanowaveguide for efficient parametric frequency conversions on chip. Using a 4-mm nanowaveguide with subwavelength mode confinement, we demonstrate second harmonic generation with efficiency over 2200% W ^−1 c m ^−2, and broadband difference frequency generation over a 4.3-THz spectral span. These allow us to generate correlated photon pairs over multiple frequency channels via spontaneous parametric down conversion, all in their fundamental spatial modes, with a coincidence to accidental ratio as high as 600. The high efficiency and dense integrability of the present chip devices may pave a viable route to scalable nonlinear applications in …

https://opg.optica.org/abstract.cfm?uri=osac-2-10-2914

J Chen, YM Sua, Z Ma, C Tang, Z Li, Y Huang


High-extinction electro-optic modulation on lithium niobate thin film

Integrated nanophotonics using lithium-niobate-on-insulator promises much-awaited solutions for scalable photonics techniques. One of its core functions is electro-optic modulation, which currently suffers limited extinction (<30  dB) due to inevitable fabrication errors. We exploit a cascaded Mach–Zehnder interferometry design to offset those errors, demonstrating up to 53 dB modulation extinction for a wide range of wavelengths between 1500 nm and 1600 nm. Together, its favorable features of chip integration, high extinction, good stability, and being broadband may prove valuable in a plethora of flourishing photonics applications.

https://opg.optica.org/abstract.cfm?uri=ol-44-5-1265

M Jin, JY Chen, YM Sua, YP Huang


High complexity, dense integrated nanophotonic circuits possessing strong non-linearities are desirable for a breadth of applications in classical and quantum optics. In this work, we study phase matching via modal engineering in lithium niobate (LN) waveguides and microring resonators on chip for second harmonic generation (SHG). By carefully engineering the geometry dispersion, we observe a 26% W^−1cm^−2 normalized efficiency for SHG in a waveguide with submicron transverse mode confinement. With similar cross-sectional dimensions, we demonstrate a phase matched microring resonator with 10 times enhancement on SHG. Our platform is capable of harnessing the strongest optical nonlinear and electro-optic effects in LN on chip with unrestricted planar circuit layouts. It offers opportunities for dense and scalable integration of efficient photonic devices with low loss and high nonlinearity.

https://opg.optica.org/abstract.cfm?uri=osac-1-1-229

JY Chen, YM Sua, H Fan, YP Huang


Efficient and highly tunable second-harmonic generation in Z-cut periodically poled lithium niobate nanowaveguides

Thin-film lithium-niobate-on-insulator (LNOI) has emerged as a superior integrated-photonics platform for linear, nonlinear, and electro-optics. Here we combine quasi-phase-matching, dispersion engineering, and tight mode confinement to realize nonlinear parametric processes with both high efficiency and wide wavelength tunability. On a millimeter-long, Z-cut LNOI waveguide, we demonstrate efficient (1900±500%W^−1cm^−2) and highly tunable (−1.71nm/K) second-harmonic generation from 1530 to 1583 nm by type-0 quasi-phase-matching. Our technique is applicable to optical harmonic generation, quantum light sources, frequency conversion, and many other photonic information processes across visible to mid-IR spectral bands.

https://opg.optica.org/abstract.cfm?uri=ol-45-13-3789

JY Chen, C Tang, ZH Ma, Z Li, YM Sua, YP Huang


Efficient electro-optical modulation on thin-film lithium niobate

Thin-film lithium niobate has emerged as an excellent, multifaceted platform for integrated photonics and opto-electronics, in both classical and quantum domains. We introduce a novel, to the best of our knowledge, dual-capacitor electrode layout for an efficient interface between electrical and optical signals on this platform. It significantly enhances the electro-optical modulation efficiency to an exceptional voltage–length product of 0.64V⋅cm, thereby lowering the required electric power by many times. This technique can boost the performance of growing applications at the interface of integrated electronics and optics, such as microwave photonics, frequency comb generation, and telecommunication transmission.

https://opg.optica.org/abstract.cfm?uri=ol-46-8-1884

M Jin, J Chen, Y Sua, P Kumar, Y Huang


Efficient frequency doubling with active stabilization on chip

Thin‐film lithium niobate (TFLN) is superior for integrated nanophotonics due to its outstanding properties in nearly all aspects: strong second‐order nonlinearity, fast and efficient electro‐optic effects, wide transparency window, and little two photon absorption and free carrier scattering. Together, they permit highly integrated nanophotonic circuits capable of complex photonic processing by incorporating disparate elements on the same chip. Yet, there has to be a demonstration that synergizes those superior properties for system advantage. Here, such a chip that capitalizes on TFLN's favorable ferroelectricity, high second‐order nonlinearity, and strong electro‐optic effects is demonstrated. It consists of a monolithic circuit integrating a Z‐cut, quasi‐phase matched microring with high quality factor and a phase modulator used in active feedback control. By Pound–Drever–Hall locking, it realizes stable frequency …

https://onlinelibrary.wiley.com/doi/abs/10.1002/lpor.202100091

JY Chen, C Tang, M Jin, Z Li, Z Ma, H Fan, S Kumar, YM Sua, YP Huang


Photon Conversion and Interaction in a Quasi-Phase-Matched Microresonator

The conversion and interaction between quantum signals at the single-photon level are essential for scalable quantum photonic information technology. Using a fully optimized periodically poled lithium niobate microring, we demonstrate ultraefficient sum-frequency generation on a chip. The external quantum efficiency reaches (65±3)% with only (104±4)-μ W pump power. At peak conversion, 3× 10− 5-noise photon is created during the cavity lifetime, which meets the requirement of quantum applications using single-photon pulses. Using a pump and signal in single-photon coherent states, we directly measure the conversion probability produced by a single pump photon to be 10− 5, which is a significant improvement from the state of the art, and the photon-photon coupling strength to be 9.1 MHz. Our results mark steady progress toward quantum nonlinear optics at the ultimate single-photon limit, with potential …

https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.16.064004

JY Chen, Z Li, Z Ma, C Tang, H Fan, YM Sua, YP Huang


Photon conversion in thin-film lithium niobate nanowaveguides: a noise analysis

Wavelength transduction of single-photon signals is indispensable to networked quantum applications, particularly those incorporating quantum memories. Lithium niobate nanophotonic devices have demonstrated favorable linear, nonlinear, and electro-optical properties to deliver this crucial function while offering superior efficiency, integrability, and scalability. Yet, their quantum noise level—a crucial metric for any single-photon-based application—has yet to be investigated. In this work, we report the first, to the best of our knowledge, study with the focus on telecom to near-visible conversion driven by a small detuned telecom pump for practical considerations in distributed quantum processing over fiber networks. Our results find the noise level to be on the order of 10^−4 photons per time-frequency mode for high conversion, allowing faithful pulsed operations. Through carefully analyzing the origins of such …

https://opg.optica.org/abstract.cfm?uri=josab-38-7-2172

H Fan, Z Ma, J Chen, Z Li, C Tang, YM Sua, Y Huang


Observation of quantum zeno blockade on chip

Overlapping in an optical medium with nonlinear susceptibilities, lightwaves can interact, changing each other’s phase, wavelength, waveform shape, or other properties. Such nonlinear optical phenomena, discovered over a half-century ago, have led to a breadth of important applications. Applied to quantum-mechanical signals, however, these phenomena face fundamental challenges that arise from the multimodal nature of the interaction between the electromagnetic fields, such as phase noises and spontaneous Raman scattering. The quantum Zeno blockade allows strong interaction between lightwaves without physical overlap between them, thus offering a viable solution for the aforementioned challenges, as indicated in recent bulk-optics experiments. Here, we report on the observation of quantum Zeno blockade on chip, where a lightwave is modulated by another in a distinct “interaction-free” manner. For …

https://www.nature.com/articles/s41598-017-13327-x

JY Chen, YM Sua, ZT Zhao, M Li, YP Huang


Chip-integrated device and methods for generating random numbers that is reconfigurable and provides genuineness verification

A device for generation of genuine random numbers, uses quantum stochastic processes in optical parametric nonlinear media. The dimensionality of the random numbers is varied from 2 to over 100,000. Their statistical properties, including the correlation function amongst random numbers, are tailored using linear and nonlinear optical circuits following the parametric nonlinear media. Both the generation and manipulation of random numbers are integrated on a single nanophotonics chip. By incorporating optoelectric effects, fast streams of random numbers are created in custom statistical properties, which are updated or reconfigured in real time, such as at 10 GHz speed. The unpredictability of the random numbers is quantifying by evaluating their min-entropy. The genuineness of quantum random numbers is tested using both statistical tools and independently verified by measuring the quantum entanglement …

https://patents.google.com/patent/US11442697B2/en

Y Huang, YM Sua, J Chen, LTT Nguyen


Phase-sensitive amplification in nanophotonic periodically poled lithium niobate waveguides

We demonstrate phase-sensitive amplification in periodically poled lithium niobate nanowavguides, achieving a net gain of 11.8 dB and an extinction ratio of 14.9 dB for 1.2-ps pump pulse with 2.4-pJ pulse energy.

https://opg.optica.org/abstract.cfm?uri=CLEO_SI-2020-SM3L.5

JY Chen, YM Sua, Z Ma, L Nguyen, YP Huang


Photon Conversion and Interaction on Chip

The conversion and interaction between quantum signals at a single-photon level are essential for scalable quantum photonic information technology. Using a fully-optimized, periodically-poled lithium niobate microring, we demonstrate ultra-efficient sum-frequency generation on chip. The external quantum efficiency reaches  with only  W pump power, improving the state-of-the-art by over one order of magnitude. At the peak conversion,  noise photon is created during the cavity lifetime, which meets the requirement of quantum applications using single-photon pulses. Using pump and signal in single-photon coherent states, we directly measure the conversion probability produced by a single pump photon to be  -- breaking the record by 100 times -- and the photon-photon coupling strength to be 9.1 MHz. Our results mark a new milestone toward quantum nonlinear optics at the ultimate single photon limit, creating new background in highly integrated photonics and quantum optical computing.

https://arxiv.org/abs/2105.00275

JY Chen, Z Li, Z Ma, C Tang, H Fan, YM Sua, YP Huang


Efficient electro-optical modulation on thin-film lithium niobate: erratum

In this erratum, we correct the corresponding results of our Letter [Opt. Lett.46, 1884 (2021)OPLEDP0146-959210.1364/OL.419597] due to the wrong impedance setting of the arbitrary waveform generator (AWG). The Letter still represents the significant advance despite the change of results.

https://opg.optica.org/abstract.cfm?uri=ol-46-18-4601

M Jin, J Chen, Y Sua, P Kumar, Y Huang


Efficient Photon Pair Generation in Thin-film Lithium Niobate Microring Resonators

We demonstrate a high purity photon pair source via parametric downcon-version in a chip-integrated lithium niobate racetrack microring resonator, observing high brightness of 6.4 MHz mW− 1 GHz− 1 at 2350 coincidence-to-accidental ratio.

https://opg.optica.org/abstract.cfm?uri=quantum-2020-QM6B.2

Z Ma, JY Chen, YM Sua, Z Li, C Tang, YP Huang


Efficient second-harmonic generation in sub-micron ppln waveguides

Efficient second-harmonic generation (SHG) is demonstrated in sub-micron periodically poled lithium niobate waveguides with normalized conversion efficiencies over 440% W− 1 cm− 2.

https://opg.optica.org/abstract.cfm?uri=ls-2018-JTu2A.87

JY Chen, YM Sua, Z Ma, C Tang, Z Li, YP Huang


Observation of Quantum Zeno Blockade in χ (2) Microresonators

We report observing all-optical modulation with a contrast of 80% via quantum Zeno blockade in a Lithium Niobate whispering-gallery-mode resonator at a pump peak power of 100µW.

https://opg.optica.org/abstract.cfm?uri=CLEO_QELS-2013-QTu3C.4

DV Strekalov, A Kowligy, YP Huang, P Kumar

2013


Highly efficient and pure few-photon source on chip

We report on multiphoton statistics of correlated twin beams produced in a periodic poled microring resonator on thin-film lithium niobate. Owing to high-cavity confinement and near-perfect quasi-phase-matching, the photon pairs are produced efficiently in single modes at rates reaching 27 MHz per μ W pump power. By using a pump laser whose pulse-width impedance matches with the cavity, those photons are further created in single longitudinal modes with purity reaching 99%, without relying on later-on filtering. With a dual-channel photon-number-resolving detection system, we obtain directly the joint detection probabilities of multiphoton states up to three photons, with high coincidence to accidental contrast for each. Used as a single-photon source, it gives heralded g H (2)(0) around 0.04 at a single-photon rate of 650 kHz on chip. The findings of our research highlight the potential of this nanophotonic …

https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.20.044033

Z Ma, JY Chen, M Garikapati, Z Li, C Tang, YM Sua, YP Huang

2023


Devices and methods for giant single-photon nonlinearities

A periodically poled microring resonator structure, a method for fabrication of the periodically poled microring resonator structure, and a method to achieve giant single-photon nonlinearity are disclosed. The strong single-photon nonlinearity in the microring resonator structure is achieved through its optimized design and fabrication procedures.

https://patents.google.com/patent/US11754908B2/en

Y Huang, J Chen

2023


DEVICES AND METHODS FOR LOW VOLTAGE OPTICAL MODULATION

An electro-optic modulation structure 110, a method for fabrication of the electro-optic modulation structure, and a method of optical modulation derived from an electro-optic modulation structure with low voltage of operation are disclosed. The low voltage operation of the electro-optic modulator is realized by designed electro-optic modulation structures that include the light confining waveguide 114, overclad layer 120 and modulating electrode structure 116 for applying modulation voltages that are directed towards a low voltage operation of the electro-optic modulation 110 device upon consideration of optimal optical loss.

https://patents.google.com/patent/US20230185119A1/en

Y Huang, YM Sua, M Jin, J Chen

2023


Photon-Pair Generation in a Heterogeneous Nanophotonic Chip

Integrated silicon photonics has played an important role in advancing the applications of quantum information and quantum science. However, it is challenging to integrate all components with state-of-the-art performance using only a homogeneous platform. Here, by combining high nonlinearity and low losses in a heterogeneous silicon platform, we efficiently generate high-quality photon pairs through spontaneous four-wave mixing in a hydrogenated amorphous silicon waveguide and route them off-chip through a low-loss silicon nitride waveguide. A record high coincidence-to-accidental ratio value of 1632.6 (±260.4) is achieved in this heterogeneous design with a photon pair generation rate of 1.94 MHz. We also showcase a wide range of multichannel photon sources with a coincidence-to-accidental ratio consistently around 200. Lastly, we measure heralded single-photons with the lowest gH(2)(0) of 0.1085 …

https://pubs.acs.org/doi/abs/10.1021/acsphotonics.3c00394

M Jin, N MacFarlane, Z Ma, YM Sua, M Foster, Y Huang, A Foster

2023


Doubly Phase Matched Wavelength Conversion in Thin-film Lithium Niobate Nanowaveguides

We demonstrate double-peak quasi-phasing matching for second-harmonic generation with high efficiency by engineering periodic poling. The results show the potential of multi-channel nonlinear optical processing on chip.

https://ieeexplore.ieee.org/abstract/document/10258765/

C Tang, S Zhu, Z Ma, Z Li, YM Sua, YP Huang

2023


Oxygen A-band absorption spectroscopy with solar photon counting and lithium niobate nanophotonic circuits

Oxygen A-band measurements can provide important information about cloud top height, cloud physical and optical thickness, and surface atmospheric pressure. So far, O2 A-band measurements are typically made with spectrometers at a spectral resolution of 40 pm (such as in the OCO-2 satellite) or a coarser resolution. This paper reports a new CubeSat measurement concept with higher spectral resolution over the O2 A-band using integrated photonic circuits and solar photon counting techniques. An integrated Micro-ring filter (MRR) chip with 10~pm resonant linewidth with an extinction ratio of 25 dB or higher is designed, fabricated, and used for precise measurements of the atmospheric oxygen A-band absorption line-shapes around 770 nm. With solar-photon counting and using a narrow-band filter made of an integrated, fast-swept MRR on LNOI, we have demonstrated a high-resolution measurement of the O2 A-band absorption spectrum, exhibiting good agreement with the HITRAN database.

https://www.frontiersin.org/articles/10.3389/frsen.2022.1064244/full

J Zhang, YM Sua, Y Hu, J Ramanathan, YP Huang

2022


Atmospheric Carbon Dioxide Absorption Measurement using Integrated Lithium Niobate Nanophotonics

We use photon counting and a sweeping high-Q microring on chip to obtain the atmospheric carbon dioxide absorption spectrum around 1572.022 nm.

https://opg.optica.org/abstract.cfm?uri=CLEO_AT-2021-AW2S.5

J Zhang, YM Sua, J Chen, J Ramanathan, C Tang, Y Hu, YP Huang

2021


Frequency Conversion and Anti-Parity-Time Symmetry Effect in Nanophotonic Thin Film Lithium Niobate Waveguide

Lithium niobate has been the one of most attractive optical and photonic materials since its exceptional performance in linear and nonlinear optics, including wide transparent window, relatively high quadratic nonlinear coefficient and strong electro-optic response. The commercialization of lithium niobate already impacts our daily life, for example, electro-optic modulator made of bulk lithium niobate has been the rock bed for nowadays information society. However, the development of Thin Film Lithium Niobate (TFLN) has lagged other nanophotonic platforms, such as silicon nitride and silicon, due to the notorious difficulty of material processing and nanofabrication. In the past five years, our lab overcame the nanofabrication difficulty in TFLN, and could routinely fabricate ultra-low propagation loss, less than 0.1 dB/cm, nanophotonic TFLN waveguide. In this dissertation, I will leverage our advantage with enhanced …

https://search.proquest.com/openview/60f91668c7b26836d9eaf5b7c90edf57/1?pq-origsite=gscholar&cbl=18750&diss=y

H Fan

2021


Observation of Anti-parity-time Symmetry on Chip

We report an on-chip realization of non-Hermitian optics with anti-Parity-Time (Anti-PT) symmetry by constructing a fully-passive, nanophotonic platform consisting of three evanescently-coupled nanowaveguides.

https://opg.optica.org/abstract.cfm?uri=FiO-2020-FTu8E.6

H Fan, J Chen, Z Zhao, J Wen, Y Huang

2020


Ultra-efficient and highly tunable frequency conversion in Z-cut periodically poled lithium niobate nanowaveguides

We demonstrate ultra-efficient (~ 1900 ± 500%W -1 cm -2 ) and highly tunable (~ 1.71 nm/K) second harmonic generation from 1530 to 1583 nm via type-0 phase matching in Z-cut periodically poled lithium niobate nanowavguides.

https://ieeexplore.ieee.org/abstract/document/9192986/

JY Chen, C Tang, Z Ma, Z Li, YM Sua, YP Huang

2020


Ultra-efficient and highly-tunable second-harmonic generation in Z-cut periodically poled lithium niobate nanowaveguides

JY Chen, C Tang, ZH Ma, Z Li, YM Sua, YP Huang

2020


Efficient quasi-phase-matched frequency conversion in a lithium niobate racetrack microresonator

We demonstrate efficient second harmonic generation in a quasi-phase-matched, high quality factor (Q 0≈ 5. 3× 10 5) racetrack microresonator. The observed normalized conversion efficiency is about 3. 8% mW− 1.

https://opg.optica.org/abstract.cfm?uri=CQO-2019-W5A.11

JY Chen, Z Ma, YM Sua, YP Huang

2019


Naturally phase matched waveguides and microrings on lithium niobate-on-insulator (LNOI)

We demonstrate naturally phase matched waveguides and microrings on chip for second-harmonic generation (SHG) with submicron transverse mode confinement.

https://opg.optica.org/abstract.cfm?uri=FiO-2018-JTu3A.100

JY Chen, YM Sua, H Fan, YP Huang

2018


Naturally Phase Matched Lithium Niobate Nanocircuits for Integrated Nonlinear Photonics

High complexity, dense integrated nanophotonic circuits possessing strong nonlinearities are desirable for a breadth of applications in classical and quantum optics. In this work, we study natural phase matching via modal engineering in lithium niobate (LN) waveguides and microring resonators on chip for second harmonic generation (SHG). By carefully engineering the geometry dispersion, we observe a  normalized efficiency for SHG in a waveguide with submicron transverse mode confinement. With similar cross-sectional dimensions, we demonstrate phase matched SHG in a microring resonator with 10 times enhancement on the out-coupled second-harmonic power. Our platform is capable of harnessing the strongest optical nonlinear and electro-optic effects in LN on chip with unrestricted planar circuit layouts. It offers opportunities for dense and scalable integration of efficient photonic devices with low loss and high nonlinearity.

https://arxiv.org/abs/1805.11476

JYC Sua, Y Meng, H Fan, Y Huang

2018


Interaction-free All-optical Modulation on Chip

We report the observation of quantum Zeno blockade on chip, where a lightwave is modulated by another in a distinct “interaction-free” manner. For quantum applications, we also verify its operations on single photons.

https://opg.optica.org/abstract.cfm?uri=FiO-2017-JW4A.12

JY Chen, YM Sua, ZT Zhao, M Li, YP Huang

2017


On-Chip Demonstration of Interaction-free Quantum Switching

Quantum Zeno blockade allows all-optical switching in a counterintuitive “interaction-free” manner. Using a lithium-niobate microdisk cavity nanofabricated on chip, we have observed phase matched sum-frequency generation and interaction-free switching between optical pulses in two tightly confined whispering-gallery modes. We have also verified that our device is suitable for nonlinear operations in a single-photon regime. Our results point to a scalable, chip-integrated platform for nonlinear optics extendable to the quantum regime.

https://opg.optica.org/abstract.cfm?uri=NLO-2017-NM2A.5

JY Chen, YM Sua, Z Zhao, M Li, YP Huang

2017