Query: integrated lithium niobate electro-optic modulators

Candidate papers:

abstract: Electro optic modulators translate high speed electronic signals into the optical domain and are critical components in modern telecommunication networks1,2 and microwave photonic systems3,4. They are also expected to be building blocks for emerging applications such as quantum photonics5,6 and non reciprocal optics7,8. All of these applications require chip scale electro optic modulators that operate at voltages compatible with complementary metal oxide semiconductor (CMOS) technology, have ultra high electro optic bandwidths and feature very low optical losses. Integrated modulator platforms based on materials such as silicon, indium phosphide or polymers have not yet been able to meet these requirements simultaneously because of the intrinsic limitations of the materials used. On the other hand, lithium niobate electro optic modulators, the workhorse of the optoelectronic industry for decades9, have been challenging to integrate on chip because of difficulties in microstructuring lithium niobate. The current generation of lithium niobate modulators are bulky, expensive, limited in bandwidth and require high drive voltages, and thus are unable to reach the full potential of the material. Here we overcome these limitations and demonstrate monolithically integrated lithium niobate electro optic modulators that feature a CMOS compatible drive voltage, support data rates up to 210 gigabits per second and show an on chip optical loss of less than 0.5 decibels. We achieve this by engineering the microwave and photonic circuits to achieve high electro optical efficiencies, ultra low optical losses and group velocity matching simultaneously. Our scalable modulator devices could provide cost effective, low power and ultra high speed solutions for next generation optical communication networks and microwave photonic systems. Furthermore, our approach could lead to large scale ultra low loss photonic circuits that are reconfigurable on a picosecond timescale, enabling a wide range of quantum and classical applications5,10,11 including feed forward photonic quantum computation.Chip scale lithium niobate electro optic modulators that rapidly convert electrical to optical signals and use CMOS compatible voltages could prove useful in optical communication networks, microwave photonic systems and photonic computation.
author_names: Cheng Wang

Mian Zhang

Xi Chen

Maxime Bertrand

Amirhassan Shams-Ansari

Sethumadhavan Chandrasekhar

Peter J Winzer

Marko Loncar
title: Integrated lithium niobate electro optic modulators operating at CMOS compatible voltages
venue: Nature
year: 2018

author_names: Mian Zhang

Cheng Wang

Prashanta Kharel

Di Zhu

Marko Loncar
title: Integrated lithium niobate electro optic modulators: when performance meets scalability
year: 2021

abstract: Since the emergence of optical fiber communications, lithium niobate (LN) has been the material of choice for electro optic modulators, featuring high data bandwidth and excellent signal fidelity. Conventional LN modulators however are bulky, expensive and power hungry, and cannot meet the growing demand in modern optical data links. Chip scale, highly integrated, LN modulators could offer solutions to this problem, yet the fabrication of low loss devices in LN thin films has been challenging. Here we overcome this hurdle and demonstrate monolithically integrated LN electro optic modulators that are significantly smaller and more efficient than traditional bulk LN devices, while preserving LN's excellent material properties. Our compact LN electro optic platform consists of low loss nanoscale LN waveguides, micro ring resonators and miniaturized Mach Zehnder interferometers, fabricated by directly shaping LN thin films into sub wavelength structures. The efficient confinement of both optical and microwave fields at the nanoscale dramatically improves the device performances featuring a half wave electro optic modulation efficiency of 1.8 Vcm while operating at data rates up to 40 Gbps. Our monolithic LN nanophotonic platform enables dense integration of high performance active components, opening new avenues for future high speed, low power and cost effective communication networks.
author_names: Cheng Wang

Mian Zhang

Brian Stern

Michal Lipson

Marko Loncar
title: Nanophotonic lithium niobate electro optic modulators.
venue: Optics express
year: 2018

abstract: Both long haul and short distance network interconnects for conventional data networks and intra /interchip data links continue to scale in complexity and bandwidth. This has signalled the emergence of the optical interconnect, with silicon photonics being the leading candidate due to its unique combination of low fabrication costs and performance enhancements. Electronic photonic integration compatibility with CMOS technology, makes integrated photonic circuits more appealing. Hence, it is very critical to make the fabrication of integrated photonic devices as foundry compatible as possible to fully utilize CMOS foundry capabilities. We have proposed a fabrication method for thin film lithium niobate (LN) based electro optic modulators which has excellent compatibility with silicon photonic foundry processes and minimizes the back end of the line processes. This paves the way for large scale production of the hybrid Silicon lithium niobate devices.
author_names: Reza Safian

Swapnajit Chakravarty

Min Teng

Leimeng Zhuang
title: Foundry compatible thin film lithium niobate electro optic modulators
venue: OPTO
year: 2020

abstract: Abstract Integrated optics is poised to revolutionize several data communication applications. The development of high performance electro optic modulators is essential for the technology to be viable. In this paper, single mode electro optic modulators in x cut lithium niobate thin film are designed, simulated, and analyzed. The single mode conditions of lithium niobate ridge waveguides are analyzed in detail. The design parameters of Y branch and separation distances between electrodes and ridge waveguides are optimized. The half wave voltage of the electro optic modulator with device lengths of 10 mm is determined. The half wave voltage length product is about 2.2 V*cm indicating the efficient electric optical modulation. This study is helpful for understand of electro optic modulator structures in lithium niobate thin film, as well as for the fabrication of high performance and multifunctional electro optic modulation devices.
author_names: Huangpu Han

Bingxi Xiang
title: Integrated electro optic modulators in x cut lithium niobate thin film
year: 2020

abstract: In this study, we designed, simulated, and optimized proton exchanged integrated Mach Zehnder modulators in a 0.5 mm thick x cut lithium niobate thin film. The single mode conditions, the mode distributions, and the optical power distribution of the lithium niobate channel waveguides are discussed and compared in this study. The design parameters of the Y branch and the separation distances between the electrodes were optimized. The relationship between the half wave voltage length production of the electro optic modulators and the thickness of the proton exchanged region was studied.
author_names: Huangpu Han

Bingxi Xiang

Tao Lin

Guangyu Chai

Shuangchen Ruan
title: Design and Optimization of Proton Exchanged Integrated Electro Optic Modulators in X Cut Lithium Niobate Thin Film
venue: Crystals
year: 2019

abstract: Author(s) Weigel, Peter Orlando Advisor(s) Mookherjea, Shayan Abstract: Electro optic modulators (EOMs) serve as a technological pillar of the modern telecommunications industry. Without these devices, which convert electrical data into optical data through one of several physical phenomena (depending on the specific technology) telecommunications channels would be severely bandwidth limited, particularly within data centers. To meet the ever increasing bandwidth demands of the industry, either more EOMs are necessary (resulting in higher power requirements) or higher bandwidth EOM technology must be developed. This thesis discusses the theory, design, fabrication, and characterization of foundry compatible hybrid silicon lithium niobate (Si LN) electro optic modulators integrated on a wafer platform, a new technology with potentially far reaching applications.By bonding a thin film of ion sliced LN crystal, which retains the crystal properties of bulk LN, to silicon waveguides in the Mach Zehnder modulator configuration, it is theoretically possible to exceed the bandwidth limitations of all Si modulators without abandoning the scalable, dense silicon on insulator (SOI) platform. These hybrid devices make use of the favorable linear electro optic Pockels effect of LN while using the high index Si waveguide to reduce the optical mode area, so that low voltage, high bandwidth devices can be realized. This thesis focuses on developing broadband EOMs with cutoff frequencies beyond 100 GHz. Developing this technology on an SOI wafer platform fabricated via photolithography in a foundry facility presents a realistic path towards next generation high speed, low power integrated EOMs.
author_names: Peter O Weigel
title: High Speed Hybrid Silicon Lithium Niobate Electro Optic Modulators Related Technologies
year: 2018

abstract: Silicon photonics is a platform that enables densely integrated photonic components and systems and integration with electronic circuits. Depletion mode modulators designed on this platform suffer from a fundamental frequency response limit due to the mobility of carriers in silicon. Lithium niobate based modulators have demonstrated high performance, but the material is difficult to process and cannot be easily integrated with other photonic components and electronics. In this manuscript, we simultaneously take advantage of the benefits of silicon photonics and the Pockels effect in lithium niobate by heterogeneously integrating silicon photonic integrated circuits with thin film lithium niobate samples. We demonstrate the most CMOS compatible thin film lithium niobate modulator to date, which has electro optic 3 dB bandwidths of 30.6 GHz and half wave voltages of 6.7 Vxcm. These modulators are fabricated entirely in CMOS facilities, with the exception of the bonding of a thin film lithium niobate sample post fabrication, and require no etching of lithium niobate.
author_names: Nicholas Boynton

Hong Cai

Michael Gehl

Shawn Arterburn

Christina M Dallo

Andrew Pomerene

Andrew L Starbuck

Dana Hood

Douglas C Trotter

Thomas Aquinas Friedmann

Christopher T DeRose

Anthony L Lentine
title: A heterogeneously integrated silicon photonic/lithium niobate travelling wave electro optic modulator.
venue: Optics express
year: 2020

abstract: The processes of the excitation of acoustic vibrations and their influence on the optical signals in integrated electro optic modulators on substrates of lithium niobate have been investigated. The resonant frequencies of the excitation of substrate vibrational modes have been determined. It has been shown that acoustic vibrations can make a significant contribution to the modulator transfer characteristic at frequencies up to several hundred megahertz, which should be taken into account when using the modulators at low frequencies, for example, as a part of fiber optic sensors.
author_names: Andrey V Varlamov

Mikhail Yu Plotnikov

Artem Aleinik

Piotr M Agrusov

I Il'ichev

Alexander V Shamray

Aleksandr A Vlasov
title: Acoustic vibrations in integrated electro optic modulators on substrates of lithium niobate
year: 2017

abstract: We demonstrate a Bragg modulator integrated on a lithium niobate on insulator platform with a footprint of 10x500 mm2 that operates at 56 Gbit/s. This electro optic Bragg reflector has a DC tuning efficiency of 23.37+ 0.55 pm/V.
author_names: Marc Reig Escale

David Pohl

Wolfgang Heni

Benedikt Baeuerle

Arne Josten

Anton Sergeyev

Juerg Leuthold

Rachel Grange
title: Integrated Electro optic Bragg Modulators in Lithium Niobate Nanowaveguides
year: 2018