About

Linbo Shao is an Assistant Professor in the Bradley Department of Electrical and Computer Engineering at Virginia Tech. He holds a PhD in Engineering Sciences from Harvard University, obtained in 2019, a Master's degree in Applied Physics from Harvard University in 2016, and a Bachelor's degree in Microelectronics from Peking University in 2014. His research focuses on nanophotonics, integrated photonics, nanofabrication, electro-optics, quantum photonics, phononics, surface acoustic waves, lithium niobate, diamond color centers, and nanofabrication. Shao's work involves developing advanced photonic and phononic devices, exploring quantum photonics applications, and innovating in nanofabrication techniques.

Research topics

• Physics
• Materials science
• Optoelectronics
• Optics
• Computer Science
• Quantum mechanics
• Electrical engineering
• Telecommunications
• Engineering
• Condensed matter physics

Selected publications

• Resonance-enhanced integrated acousto-optic beam steering

  arXiv (Cornell University) · 2026-03-18

  preprintOpen access

  Optical beam steering is a key technology for free-space optical communication, sensing, and imaging. Mechanical beam steering systems suffer from limited scanning speed and bulky form factors, while existing solid-state solutions rely on pixelated synthetic aperture that requires complex fabrication and control architectures. Integrated acousto-optic beam steering (AOBS) is an emerging technology that enables continuous one-dimensional beam steering using integrated acoustic transducers and fixed-wavelength laser sources. Here, we integrate AOBS with an optical ring resonator on the same thin-film lithium niobate (TFLN) platform to significantly enhance beam steering efficiency and system functionality. The resulting device achieves a resonance-enhanced beam steering efficiency of up to 20% over a 18 degrees field of view. Moreover, by leveraging integrated electro-optic control, we dynamically lock the ring-resonator's resonance to a chirped laser frequency, enabling frequency-modulated continuous-wave (FMCW) LiDAR operation. By combining lithium niobate's piezoelectric and electro-optic properties, this work establishes a compact, efficient, and scalable beam-steering platform with co-integrated acousto-optic modulation and electro-optic control for multifunctional applications.

  PublisherDOI

• Motional-Current-Sensing Method and Simplified Closed-Loop Control Strategy for Piezoelectric-Resonator-based DC-DC Converters

  ArXiv.org · 2026-05-14

  articleOpen access

  Piezoelectric resonators (PRs) have been seen as a competitive alternative to magnetic components. In PR-based converters, the motional current (in the LC series branch of the equivalent circuit) is vital for control proposes but cannot be measured directly. The difficulties to detect the zero-crossing points or to measure the amplitude of the motional current has been one of the most dominating obstacles that complicates the control strategies and limits the frequency range of the PR-based converters. This work discusses a ring-dot shaped piezoelectric transformer (PT) based motional current sensing method that provides current information with low-delay, low-loss and intrinsic isolation. It is physically proven that the proposed method is robust with various non-ideal factors of the piezoceramic and circuit implementation. Based on this, an event-driven control strategy is introduced, consisting of only a finite state machine, a PI loop, a low-speed ADC and several comparators. Experiments on a step-down PR-based converter verify that the proposed approach realize ZVS for all transitions within a switching cycle with reduced hardware and software resources, enhances stability and is capable of self-startup.

  PublisherOA PDF

• Nonlinear exceptional points in an integrated acoustic-wave oscillator for longwave infrared sensing

  ArXiv.org · 2026-04-30

  articleOpen access1st authorCorresponding

  Exceptional points (EP) featuring enhanced responsivity and rich dynamics have attracted extensive attentions in device developments and sensing applications. However, it remains debated whether employing EP systems is beneficial in practical sensing applications. Here, we demonstrate that a nonlinear EP in our microwave-frequency acoustic-wave oscillator improves longwave infrared (LWIR) detection under practical conditions. By phase tuning the nonlinear gain, our detector can be operated at different conditions with respect to the nonlinear EP. Compared with operation away from EP, our detector at EP shows a 33-fold improvement in responsivity and an 8.75-fold extension of 3-dB bandwidth. We observe a 6-fold enhancement in signal-to-noise ratio at an input modulation frequency of 6.2 kHz. At the incident LWIR wavelength of 9.6 um, our detector at EP exhibits a noise equivalent power (NEP) of 310 pW*Hz^-1/2 at input frequency of 10 kHz, yielding a figure of merit, product of NEP and time constant, of 9.87*10^-3 pW*Hz^-3/2, a 10-fold improvement over operation away from EP. Our integrated acoustic devices offer a versatile platform for exploring noise dynamics and developing practical sensors that exploit non-Hermitian nonlinearities.

  PublisherOA PDF

• Microwave-acoustic-based isolated gate driver for power electronics

  Communications Engineering · 2026-05-05

  articleOpen access

  Electrical isolation is critical to ensure safety and minimize electromagnetic interference (EMI), yet existing methods struggle to simultaneously transmit power and signals through a unified channel. Here we demonstrate a mechanically-isolated gate driver based on microwave-frequency surface acoustic wave (SAW) device on lithium niobate that achieves galvanic isolation of 2.75 kV with ultralow isolation capacitance (0.032 pF) over 1.25 mm mechanical propagation length, delivering 13.4 V open-circuit voltage and 44.4 mA short-circuit current. We demonstrate isolated gate driving for a gallium nitride (GaN) high-electron-mobility transistor, achieving a turn-on time of 108.8 ns and validate its operation in a buck converter. In addition, our SAW device operates over an ultrawide temperature range from 0.5 K (-272.6 °C) to 544 K (271 °C). The microwave-frequency SAW devices offer inherent EMI immunity and potential for heterogeneous integration on multiple semiconductor platforms, enabling compact, high-performance isolated power and signal transmission in advanced power electronics. Liyang Jin and colleagues report an isolated SAW-based gate driver enabling power and signal co-transmission through one channel. This approach offers ultralow capacitance and EMI immunity for compact, high-performance isolated power electronics.

  PublisherDOI

• Magnet-Free Nonreciprocal frequency conversion using Sequential Temporal modulation: Theory and Simulations

  ArXiv.org · 2026-04-15

  articleOpen accessSenior author

  Nonreciprocal conversion is essential for protecting sources and enabling unidirectional signal routing in photonic, phononic, electronics, and quantum systems, yet conventional implementations rely on magnetic bias that could be challenging to integrate on chip. We propose a magnet-free scheme for frequency-domain nonreciprocity based on sequential, time-gated couplings in a three-mode system. By activating interactions in a fixed temporal order, the forward and reverse frequency conversion pathways acquire unequal dwell times in a lossy intermediate mode, producing strong nonreciprocity without requiring nonlinearities or magnetic materials. Using a harmonic-balance formulation and a Dyson-Born expansion, we derive a compact analytical expression for the isolation ratio that reveals the roles of Floquet sidebands, duty-cycle control, modulation frequency, and dissipation. The results are confirmed by direct time-domain simulations over a wide parameter range. From these results, we extract practical design rules for optimizing isolation through temporal sequencing, loss engineering, and modulation timing. The framework is general and directly applicable to integrated platforms in photonics, phononics, microwave electronics, and superconducting circuits.

  PublisherOA PDF

• Magnet-Free Nonreciprocal frequency conversion using Sequential Temporal modulation: Theory and Simulations

  arXiv (Cornell University) · 2026-04-15

  preprintOpen accessSenior author

  Nonreciprocal conversion is essential for protecting sources and enabling unidirectional signal routing in photonic, phononic, electronics, and quantum systems, yet conventional implementations rely on magnetic bias that could be challenging to integrate on chip. We propose a magnet-free scheme for frequency-domain nonreciprocity based on sequential, time-gated couplings in a three-mode system. By activating interactions in a fixed temporal order, the forward and reverse frequency conversion pathways acquire unequal dwell times in a lossy intermediate mode, producing strong nonreciprocity without requiring nonlinearities or magnetic materials. Using a harmonic-balance formulation and a Dyson-Born expansion, we derive a compact analytical expression for the isolation ratio that reveals the roles of Floquet sidebands, duty-cycle control, modulation frequency, and dissipation. The results are confirmed by direct time-domain simulations over a wide parameter range. From these results, we extract practical design rules for optimizing isolation through temporal sequencing, loss engineering, and modulation timing. The framework is general and directly applicable to integrated platforms in photonics, phononics, microwave electronics, and superconducting circuits.

  PublisherDOI

• Low-loss phononic integrated circuits based on a silicon nitride-lithium niobate platform

  arXiv (Cornell University) · 2026-03-29

  preprintOpen accessSenior author

  Microwave-frequency acoustic waves in solids have emerged as a versatile platform for both classical and quantum applications. While phononic integrated devices and circuits are being developed on various material platforms, an ideal phononic integrated circuit (PnIC) platform should simultaneously support low-loss waveguide structures, high-quality-factor resonators, high-performance modulators, and efficient electromechanical transducers. Here, we establish a low-loss gigahertz-frequency PnIC platform based on patterned thin-film silicon nitride (SiN) on lithium niobate (LN) substrate. We develop low-loss PnIC building blocks including waveguides, directional couplers, and high-quality-factor (high-Q) ring resonators. As an application, we demonstrate a 1-GHz phononic oscillator based on a ring resonator, reaching a low phase noise of -159.0 dBc/Hz at a 100-kHz offset frequency. Our low-loss PnICs could meet the requirements in microwave acoustics, quantum phononics, and integrated hybrid systems combining phonons, photons, superconducting qubits, and solid-state defects.

  PublisherDOI

• Resonance-enhanced integrated acousto-optic beam steering

  ArXiv.org · 2026-03-18

  articleOpen access

  Optical beam steering is a key technology for free-space optical communication, sensing, and imaging. Mechanical beam steering systems suffer from limited scanning speed and bulky form factors, while existing solid-state solutions rely on pixelated synthetic aperture that requires complex fabrication and control architectures. Integrated acousto-optic beam steering (AOBS) is an emerging technology that enables continuous one-dimensional beam steering using integrated acoustic transducers and fixed-wavelength laser sources. Here, we integrate AOBS with an optical ring resonator on the same thin-film lithium niobate (TFLN) platform to significantly enhance beam steering efficiency and system functionality. The resulting device achieves a resonance-enhanced beam steering efficiency of up to 20% over a 18 degrees field of view. Moreover, by leveraging integrated electro-optic control, we dynamically lock the ring-resonator's resonance to a chirped laser frequency, enabling frequency-modulated continuous-wave (FMCW) LiDAR operation. By combining lithium niobate's piezoelectric and electro-optic properties, this work establishes a compact, efficient, and scalable beam-steering platform with co-integrated acousto-optic modulation and electro-optic control for multifunctional applications.

  PublisherOA PDF

• Photonics-integrated power electronics: A review and perspective

  Applied Physics Express · 2026-05-18

  articleOpen access

  Abstract The rapid advancement of WBG and UWBG power semiconductors has propelled modern power electronics toward high switching frequencies and power densities. However, these high-stress operating regimes introduce severe EMI and isolation challenges. To overcome these bottlenecks, the integration of photonic technologies into power electronic systems has emerged as a promising solution. This article presents a comprehensive review and perspective on the state-of-the-art in optical power electronics. We systematically examine the underlying physics, structural innovations, and hardware demonstrations of key optical components for power applications, including advanced photodetectors, optically-controlled power semiconductor switches, optocoupler-based signal isolators, photovoltaic-based auxiliary power supplies, monolithically integrated optical driver integrated circuits (ICs), and the optical sensors for voltage, current, and temperature monitoring. By benchmarking current technological capabilities and outlining future roadmaps, this review provides a reference for developing the next generation of resilient, ultra-compact, and intelligent optical power electronics.

  PublisherDOI

• Low-loss phononic integrated circuits based on a silicon nitride-lithium niobate platform

  arXiv (Cornell University) · 2026-03-29

  articleOpen accessSenior author

  Microwave-frequency acoustic waves in solids have emerged as a versatile platform for both classical and quantum applications. While phononic integrated devices and circuits are being developed on various material platforms, an ideal phononic integrated circuit (PnIC) platform should simultaneously support low-loss waveguide structures, high-quality-factor resonators, high-performance modulators, and efficient electromechanical transducers. Here, we establish a low-loss gigahertz-frequency PnIC platform based on patterned thin-film silicon nitride (SiN) on lithium niobate (LN) substrate. We develop low-loss PnIC building blocks including waveguides, directional couplers, and high-quality-factor (high-Q) ring resonators. As an application, we demonstrate a 1-GHz phononic oscillator based on a ring resonator, reaching a low phase noise of -159.0 dBc/Hz at a 100-kHz offset frequency. Our low-loss PnICs could meet the requirements in microwave acoustics, quantum phononics, and integrated hybrid systems combining phonons, photons, superconducting qubits, and solid-state defects.

  PublisherOA PDF

Frequent coauthors

• Marko Lončar

  75 shared

• Neil Sinclair

  Harvard University

  45 shared

• Di Zhu

  National University of Singapore

  38 shared

• Mian Zhang

  37 shared

• Mengjie Yu

  32 shared

• Yaowen Hu

  Harvard University

  25 shared

• Benjamin Pingault

  Harvard University

  22 shared

• Smarak Maity

  22 shared

Labs

• Bradley Department of Electrical and Computer EngineeringPI

Education

• Ph.D., School of Engineering and Applied Science

  Harvard University

  2019

• B.S., Electronic Engineering and Computer Science

  Peking University

  2014