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David Marpaung

Publications and source records attributed to David Marpaung.

At least 19 recordsLinked to original sources
arXiv2026

Giant backward Brillouin interaction in generic InP integrated photonics

We report the first measurement of backward stimulated Brillouin scattering (SBS) in generic InP waveguides, supporting enhanced Brillouin gain of $g_B/Q_m = 3.5 \pm 0.6~\text{W}^{-1} \text{m}^{-1}$ mediated by weakly-guided pressure waves in InGaAsP. This leads to SBS gain coefficients as high as $737 \pm 54~\text{W}^{-1} \text{m}^{-1}$, observed in a mature, foundry-accessible photonic integration platform.

physics.optics↗
arXiv2026

Integrated lithium niobate microwave photonics: Driving next-generation wireless technologies

Integrated microwave photonics (MWP) offers a powerful paradigm for handling high-speed microwave signals within chip-scale optical systems. It provides a cost-effective solution to address bandwidth, tunability, and loss bottlenecks of electronics-based radio frequency (RF) systems. The recently emerged thin-film lithium niobate (TFLN) photonic platform, with its exceptional electro-optic (EO) properties, low loss, and scalability, has shown promise to reshape the MWP landscape. Here, we discuss the performance implications of state-of-the-art TFLN photonic devices for MWP applications and offer insights into the emerging trends for next-generation wireless networks. In particular, the unparalleled EO bandwidth enables direct optical generation, processing, and reception of millimeter-wave or even terahertz (THz) signals, significantly expanding the operation frequency range of MWP systems. The low drive voltages and linearity of TFLN modulators lead to an unprecedented operation regime of radio-over-fiber (RoF) systems, featuring net gain, low noise figure and large dynamic range, simultaneously. The availability of a versatile device toolkit, combined with low optical loss and scalability, further supports the transition from traditional tabletop MWP systems to chip-scale solutions, with advanced functionalities, compact footprint, and enhanced system robustness. As the TFLN industrial ecosystem rapidly matures, TFLN-based MWP technology has the potential to deliver transformative solutions to future 6G integrated sensing and communication networks.

physics.optics↗
arXiv2026

Thermoelastic surface acoustic waves in low-loss silicon nitride integrated circuits

Acousto-optic modulation in photonic integrated circuits harness the applications that include signal processing, quantum photonics and microwave photonics. However, silicon nitride ($\rm{Si_3N_4}$), as a main-stream low-loss scalable photonic platform, suffers from the lack of piezoelectric effect and therefore the hybrid co-integration with other materials is always required for acousto-optic modulation. Here, we employed thermoelastic surface acoustic waves (SAW) in a 8 dB/m propagation loss $\rm{Si_3N_4}$ integrated circuits without adding extra materials. A phase modulation efficiency enhancement of 13.6 dB is realized with a multi-pass configuration. Furthermore, a single-sideband intermodal scattering with a suppression ratio of 8 dB is measured and an intensity modulation is observed by incorporating the phase modulation into a ring resonator spectral. This thermoelastic SAW technique, as an initial step of acousto-optic modulation in low-loss $\rm{Si_3N_4}$ platform, is promising for integrated microwave photonics and programmable photonics applications.

physics.optics↗
arXiv2025

Suspended Z-cut lithium niobate waveguides for stimulated Brillouin scattering

On-chip stimulated Brillouin scattering (SBS) has recently been demonstrated in thin-film lithium niobate (TFLN), an emerging material platform for integrated photonics offering large electro-optic and nonlinear properties. While previous work on SBS in TFLN have focused on surface SBS, in this contribution we experimentally demonstrate, for the first time, backward intra-modal SBS generation in suspended Z-cut TFLN waveguides. Our results show trapping of multiple acoustic modes in this structure, featuring a multi-peak Brillouin gain spectrum due to the excitation of higher-order acoustic modes. The findings expand the TFLN waveguide platform exploration for SBS interactions and provide a crucial step towards realizing optical processors for microwave signals or sensors integrated on TFLN.

physics.optics↗
arXiv2024

Brillouin photonics engine in the thin-film lithium niobate platform

Stimulated Brillouin scattering (SBS) is revolutionizing low-noise lasers and microwave photonic systems. However, despite extensive explorations of a low-loss and versatile integrated platform for Brillouin photonic circuits, current options fall short due to limited technological scalability or inadequate SBS gain. Here we introduce the thin-film lithium niobate (TFLN) platform as the go-to choice for integrated Brillouin photonics applications. We report the angle-dependent strong SBS gain in this platform, which can overcome the intrinsic propagation loss. Furthermore, we demonstrate the first stimulated Brillouin laser in TFLN with a tuning range > 20 nm and utilize it to achieve high-purity RF signal generation with an intrinsic linewidth of 9 Hz. Finally, we devise a high-rejection Brillouin-based microwave photonic notch filter, for the first time, integrating an SBS spiral, an on-chip modulator, and a tunable ring all within the same platform. This TFLN-based Brillouin photonics engine uniquely combines the scalability of this platform and the versatility of SBS. Moreover, it bridges SBS with other functionalities in the TFLN platform, unlocking new possibilities for Brillouin-based applications with unparalleled performances.

physics.optics↗
arXiv2024

Stimulated Brillouin scattering in a non-suspended ultra-low-loss thick-SOI platform

Silicon photonics, with its CMOS compatibility and high integration density, has enabled a wide range of novel applications. Harnessing stimulated Brillouin scattering (SBS), an optomechanic interaction between optical and GHz acoustic waves, in silicon-on-insulator (SOI) platforms attracts great interests for its potential in narrow-linewidth lasers and microwave photonics. However, the poor optoacoustic overlap in silicon nanowires on conventional SOI platforms has previously restricted the observation of SBS signals to suspended silicon waveguide structures. In this work, we report, for the first time, the SBS response in a non-suspended ultra-low-loss thick-SOI waveguide platform. The SBS process in this 3~$\mu$m thick SOI platform is enabled by a leaky acoustic mode that coexists with the optical mode in the waveguide core, resulting in enhanced optoacoustic overlap. We measured a Brillouin gain coefficient of 2.5 m$^{-1}$W$^{-1}$ and 1.9 m$^{-1}$W$^{-1}$ at 37.6 GHz for the rib and strip waveguide, respectively. This work paves the way for Brillouin-based applications in non-suspended ultra-low-loss silicon photonics systems.

physics.optics↗
arXiv2024

Surface acoustic waves Brillouin photonics on a silicon nitride chip

Seamlessly integrating stimulated Brillouin scattering (SBS) in a low-loss and mature photonic integration platform remains a complicated task. Virtually all current approaches fall short in simultaneously achieving strong SBS, low losses, and technological scalability. In this work we incorporate stong SBS into a standard silicon nitride platform by a simple deposition of a tellurium oxide layer, a commonly used material for acousto-optic modulators. In these heterogeneously integrated waveguides, we harness novel SBS interactions actuated by surface acoustic waves (SAWs) leading to more than two orders of magnitude gain enhancement. Three novel applications are demonstrated in this platform: (i) a silicon nitride Brillouin amplifier with 5 dB net optical gain, (ii) a compact intermodal stimulated Brillouin laser (SBL) capable of high purity radio frequency (RF) signal generation with 7 Hz intrinsic linewidth, and (iii) a widely tunable microwave photonic notch filter with ultra-narrow linewidth of 2.2 MHz enabled by Brillouin induced opacity. These advancements can unlock an array of new RF and optical technologies to be directly integrated in silicon nitride.

physics.optics↗
arXiv2024

Integrated RF Photonic Front-End Capable of Simultaneous Cascaded Functions

Integrated microwave photonic (MWP) front-ends are capable of ultra-broadband signal reception and processing. However, state-of-the-art demonstrations are limited to performing only one specific functionality at any given time, which fails to meet the demands of advanced radio frequency applications in real-world electromagnetic environments. In this paper, we present a major departure from the current trend, which is a novel integrated MWP front-end capable of simultaneous cascaded functions with enhanced performances. Our integrated MWP front-end can delay or phase-shift signals within the selected frequency band while simultaneously suppressing noise signals in other frequency bands, resembling the function of a conventional RF front-end chain. Moreover, we implement an on-chip linearization technique to improve the spurious-free dynamic range of the system. Our work represents a paradigm shift in designing RF photonic front-ends and advancing their practical applications.

physics.optics↗
arXiv2024

Programmable multifunctional integrated microwave photonic circuit on thin-film lithium niobate

Microwave photonics, with its advanced high-frequency signal processing capabilities, is expected to play a crucial role in next-generation wireless communications and radar systems. The realization of highly integrated, high-performance, and multifunctional microwave photonic links will pave the way for its widespread deployment in practical applications, which is a significant challenge. Here, leveraging thin-film lithium niobate intensity modulator and programmable cascaded microring resonators, we demonstrate for the first time a tunable microwave photonic notch filter that simultaneously achieves high level of integration along with high dynamic range, high link gain, low noise figure, and ultra-high rejection ratio. Additionally, this programmable on-chip system is multifunctional, allowing for the dual-band notch filter and the suppression of the high-power interference signal. This work demonstrates the potential applications of the thin-film lithium niobate platform in the field of high-performance integrated microwave photonic filtering and signal processing, facilitating the advancement of microwave photonic system towards practical applications.

physics.optics↗
arXiv2024

Brillouin nonlinearity characterizations of a high refractive index silicon oxynitride platform

Silicon oxynitride (SiON) is a low-loss and versatile material for linear and nonlinear photonics applications. Controlling the oxygen-to-nitrogen (O/N) ratio in SiON provides an effective way to engineer its optical and mechanical properties, making it a great platform for the investigation of on-chip optomechanical interactions, especially the stimulated Brillouin scattering (SBS). Here we report the Brillouin nonlinearity characterization of a SiON platform with a specific O/N ratio (characterized by a refractive index of $n=1.65$). First, we introduce this particular SiON platform with fabrication details. Subsequently, we discuss various techniques for the on-chip Brillouin nonlinearity characterizations. In particular, we focus on the intensity-modulated pump-probe lock-in amplifier technique, which enables ultra-sensitive characterization. Finally, we analyze the Brillouin nonlinearities of this SiON platform and compare them with other SiON platforms. This work underscores the potential of SiON for on-chip Brillouin-based applications. Moreover, it paves the way for Brillouin nonlinearity characterization across various material platforms.

physics.optics↗
arXiv2023

On-Chip Stimulated Brillouin Scattering via Surface Acoustic Waves

Surface acoustic wave (SAW) devices are ubiquitously used for signal processing and filtering, as well as mechanical, chemical and biological sensing, and show promise as quantum transducers. However, nowadays most SAWs are excited and driven via electromechanical coupling and interdigital transducers (IDTs), limiting operation bandwidth and flexibility. Novel ways to coherently excite and detect SAWs all-optically interfaced with photonic integrated circuits are yet elusive. Backward Stimulated Brillouin scattering (SBS) provides strong coherent interactions between optical and acoustic waves in chip-scale waveguides, however, demonstrations have been limited to single longitudinal waves in the waveguide core. Here, we numerically model and experimentally demonstrate surface acoustic wave stimulated Brillouin scattering (SAW-SBS) on a photonic chip. We designed and fabricated tailored waveguides made out of GeAsSe glass that show good overlap between SAWs at 3.81 GHz and guided optical modes, without requiring a top cladding. We measure a 225 W$^{-1}$m$^{-1}$ Brillouin gain coefficient of the surface acoustic resonance and linewidth narrowing to 40 MHz. Experimentally accessing this new regime of stimulated Brillouin scattering opens the door for novel on-chip sensing and signal processing applications, strong Brillouin interactions in materials that do not provide sufficient acoustic guidance in the waveguide core as well as excitation of surface acoustic waves in non-piezoelectric materials.

physics.optics↗
arXiv2023

Observation of a Brillouin dynamic grating in silicon nitride waveguides

Brillouin enhanced four wave mixing in the form of a Brillouin dynamic grating (BDG) enables a uniquely tunable filter, whose properties can be tuned by purely optical means. This makes the BDG a valuable tool in microwave photonics (MWP). BDGs have been studied extensively in fibers, but the only observation in an integrated platform required exotic materials. Unlocking BDG in a standard and mature platform will enable its integration into large-scale circuits. Here we demonstrate the first observation of a BDG in a silicon nitride (Si$_3$N$_4$) waveguide. We also present a new, optimized design, which will enhance the BDG response of the waveguide, unlocking a path to large-scale integration into MWP circuits.

physics.optics↗
arXiv2023

Stimulated Brillouin scattering in tellurite-covered silicon nitride waveguides

Stimulated Brillouin scattering (SBS), a coherent nonlinear effect coupling acoustics and optics, can be used in a wide range of applications such as Brillouin lasers and tunable narrowband RF filtering. Wide adoption of such technologies however, would need a balance of strong Brillouin interaction and low optical loss in a structure compatible with large scale fabrication. Achieving these characteristics in scalable platforms such as silicon and silicon nitride remains a challenge. Here, we investigate a scalable Brillouin platform combining low loss Si$_3$N$_4$ and tellurium oxide (TeO$_2$) exhibiting strong Brillouin response and enhanced acoustic confinement. In this platform we measure a Brillouin gain coefficient of 8.5~m$^{-1}$W$^{-1}$, exhibiting a twenty fold improvement over the largest previously reported Brillouin gain in a Si$_3$N$_4$ platform. Further, we demonstrate cladding engineering to control the strength of the Brillouin interaction. We utilized the Brillouin gain and loss resonances in this waveguide for an RF photonic filter with more than 15 dB rejection and 250 MHz linewidth. Finally, we present a pathway by geometric optimization and cladding engineering to a further enhancement of the gain coefficient to 155~m$^{-1}$W$^{-1}$, a potential 400 times increase in the Brillouin gain coefficient.

physics.optics↗
arXiv2023

Linearized Integrated Microwave Photonic Circuit for Filtering and Phase Shifting

Photonic integration, advanced functionality, reconfigurability, and high RF performance are key features in integrated microwave photonic systems that are still difficult to achieve simultaneously. In this work, we demonstrate an integrated microwave photonic circuit that can be reconfigured for two distinct RF functions, namely, a tunable notch filter and a phase shifter. We achieved $>$50dB high-extinction notch filtering over 6-16 GHz and 2$π$ continuously tunable phase shifting over 12-20 GHz frequencies. At the same time, we implemented an on-chip linearization technique to achieve a spurious-free dynamic range of more than 120$\rm{dB}\cdot \rm{Hz}^{4/5}$ for both functions. Our work combines multi-functionality and linearization in one photonic integrated circuit, and paves the way to reconfigurable RF photonic front-ends with very high performance.

physics.app-ph↗
arXiv2023

Brillouin and Kerr nonlinearities of a low-index silicon oxynitride platform

Nonlinear optical effects including stimulated Brillouin scattering (SBS) and four-wave mixing (FWM) play an important role in microwave photonics, optical frequency combs, and quantum photonics. Harnessing SBS and FWM in a low-loss and versatile integrated platform would open the path to building large-scale Brillouin/Kerr-based photonic integrated circuits. In this letter, we investigate the Brillouin and Kerr properties of a low-index (n=1.513 @ 1550 nm) silicon oxynitride (SiON) platform. We observed, for the first time, backward SBS in SiON waveguides with a Brillouin gain coefficient of 0.3$\rm m^{-1}W^{-1}$, which can potentially be increased to 0.95$\rm m^{-1}W^{-1}$ by just tailoring the waveguide cross-section. We also performed FWM experiments in SiON rings and obtained the nonlinear parameter $γ$, of 0.02 $\rm m^{-1}W^{-1}$. Our results point to a low-loss and low-index photonic integrated platform that is both Brillouin and Kerr active.

physics.optics↗
arXiv2022

Ultra-Efficient On-Chip Supercontinuum Generation from Sign-Alternating-Dispersion Waveguides

Fully integrated supercontinuum sources on-chip are critical to enabling applications such as portable and mechanically-stable medical imaging devices, chemical sensing and LiDAR. However, the low-efficiency of current supercontinuum generation schemes prevent full on-chip integration. In this letter, we present a scheme where the input energy requirements for integrated supercontinuum generation is drastically lowered by orders of magnitude, for bandwidth generation of the order of 500 to 1000 nm. Through sign-alternating the dispersion in a CMOS compatible silicon nitride waveguide, we achieve an efficiency enhancement by factors reaching 3800. We show that the pulse energy requirement for large bandwidth supercontinuum generation at high spectral energy (e.g., 1/e level) is lowered from nanojoules to 6 picojoules. The lowered pulse energy requirements enables that chip-integrated laser sources, such as mode-locked heterogeneously or hybrid integrated diode lasers, can be used as a pump source, enabling fully integrated on-chip high-bandwidth supercontinuum sources.

physics.optics↗
arXiv2022

Ultrahigh Dynamic Range and Low Noise Figure Programmable Integrated Microwave Photonic Filter

Microwave photonics (MWP) has adopted a number of important concepts and technologies over the recent pasts, including photonic integration, versatile programmability, and techniques for enhancing key radio frequency performance metrics such as the noise figure and the dynamic range. However, to date, these aspects have not been achieved simultaneously in a single circuit. Here, we demonstrate, for the first time, a multi-functional integrated microwave photonic circuit that enables on-chip programmable filtering functions while achieving record-high key radio frequency metrics of >120 dB.Hz dynamic range and 15 dB of noise figure that are previously unreachable. We unlock this unique feature by versatile complex spectrum tailoring using an all integrated modulation transformer and a double injection ring resonator as a multi-function optical filtering component. This work breaks the conventional and fragmented approach of integration, functionality and performance that currently prevents the adoption of integrated MWP systems in real applications.

physics.app-ph↗