Optical Parametric Oscillator (OPO) Research Papers
Multi-octave frequency comb from an ultra-low-threshold nanophotonic parametric oscillator
Authors: Ryoto Sekine, Robert M. Gray, Luis Ledezma, Selina Zhou, Qiushi Guo & Alireza Marandi
Publisher: Nature Photonics
Executive Summary
Frequency combs are one of the most important technologies in modern photonics, enabling precise measurements, ultra-fast optical systems, advanced spectroscopy, and next-generation communications. By producing a series of evenly spaced optical frequencies that remain phase-coherent across a broad spectrum, frequency combs provide a powerful foundation for applications that require exceptional accuracy and stability. Expanding the spectral bandwidth of these combs while reducing the energy required to generate them has been a longstanding challenge for integrated photonic devices.
This research demonstrates a significant breakthrough by achieving multi-octave frequency comb generation on a nanophotonic lithium niobate chip using an optical parametric oscillator (OPO). Through advanced dispersion engineering and an ultra-low-threshold device design, the team generated coherent frequency combs spanning multiple octaves while requiring only femtojoules of pump energy—orders of magnitude less than conventional integrated approaches.
The exceptionally low energy requirement enabled access to a previously unexplored operating regime for optical parametric oscillators, where highly efficient and stable coherent spectral broadening becomes possible. This approach overcomes one of the primary limitations of existing integrated frequency comb technologies, which typically rely on energy-intensive nonlinear processes to achieve broad spectral coverage.
In addition to demonstrating dramatic improvements in efficiency, the research confirmed that the generated frequency combs maintain their coherence across the expanded spectrum, a critical requirement for high-precision scientific and industrial applications. The work also establishes a clear path toward even broader spectral coverage and higher-performance integrated photonic systems through continued advances in device engineering.
By combining ultra-broad bandwidth with unprecedented energy efficiency in a compact, chip-scale platform, this research represents an important milestone for integrated nonlinear photonics. The demonstrated technology has the potential to accelerate the development of next-generation optical systems for spectroscopy, precision metrology, ultrafast science, optical communications, and quantum technologies, while making these capabilities more scalable, practical, and energy efficient than ever before.
Octave-spanning tunable infrared parametric oscillators in nanophotonics
Authors: Luis Ledezma, Arkadev Roy, Luis Costa, Ryoto Sekine, Robert Gray, Qiushi Guo, Rajveer Nehra, Ryan M. Briggs, and Alireza Marandi
Publisher: Science Advances
Executive Summary
Widely tunable laser sources are a foundational technology for modern photonics, enabling applications ranging from high-speed optical communications to precision sensing and molecular spectroscopy. In particular, the mid-infrared wavelength range (beyond 2 μm) is critical because many molecules exhibit unique optical signatures in this region, making it especially valuable for chemical detection, environmental monitoring, and advanced sensing systems. Despite their importance, achieving broad wavelength tuning on compact integrated photonic chips has remained a significant technical challenge.
This research demonstrates a major advancement in integrated photonics through the development of an ultrawidely tunable optical parametric oscillator (OPO) built on a dispersion-engineered, periodically poled lithium niobate (PPLN) nanophotonic platform. By carefully engineering the device and using 100-nanosecond pump pulses near 1 μm, the team achieved continuous wavelength tuning from 1.53 μm to 3.25 μm on a single chip while producing output powers in the tens of milliwatts.
The results represent the first nanophotonic optical parametric oscillator capable of octave-spanning wavelength tuning that extends into the mid-infrared. This broad tuning range significantly exceeds previous integrated implementations, which have largely been limited to narrower infrared bands or visible wavelengths.
Beyond the technical achievement, this work highlights the potential of lithium niobate nanophotonics as a highly versatile platform for next-generation integrated light sources. Compact, chip-scale devices with broad wavelength tunability can reduce the size, complexity, and cost of photonic systems while enabling new capabilities across scientific and industrial applications.
This breakthrough opens the door to a new class of integrated photonic technologies for spectroscopy, sensing, telecommunications, and other applications that require flexible, coherent light sources across a wide range of wavelengths. By extending octave-spanning tunability into the mid-infrared on a single chip, this research establishes an important milestone toward scalable, high-performance photonic systems that were previously achievable only with much larger and more complex optical setups.
Large-scale time-multiplexed nanophotonic parametric oscillators
Authors: Robert M. Gray, Ryoto Sekine, Luis Ledezma, Gordon H.Y. Li, Selina Zhou, Arkadev Roy, Midya Parto, Alireza Marandi
Publisher: Newton
Executive Summary
Nonlinear optical resonators are fundamental building blocks of advanced photonic technologies, enabling light to be manipulated in ways that support high-speed sensing, communications, and optical computing. While networks of coupled resonators have the potential to solve complex computational problems and process information at the speed of light, existing implementations have been limited by their scale, efficiency, and lack of programmability. Building large, practical networks of independent nonlinear resonators on a single chip has remained a significant challenge.
This research demonstrates the first large-scale implementation of time-multiplexed optical parametric oscillators (OPOs) on a nanophotonic lithium niobate platform, marking an important milestone toward scalable all-optical computing systems. The team successfully realized 70 independent OPOs operating on a single chip at a repetition rate of 17.5 GHz, while requiring only a few picojoules of pump energy to operate. This exceptionally low threshold highlights the strong nonlinear performance of lithium niobate and significantly improves the efficiency of integrated photonic resonators compared with previous approaches.
A critical achievement of this work was verifying that each oscillator operates independently. Using interferometric measurements, the researchers confirmed the quantum-random phase behavior of the individual OPOs, demonstrating that the time-multiplexed architecture preserves the independence required for reliable large-scale photonic networks. This capability overcomes a major obstacle that has historically limited the development of programmable nonlinear photonic systems.
Beyond demonstrating a record-scale array of integrated OPOs, the research introduces a practical architecture for building programmable networks with all-to-all connections using only a small number of additional integrated components. This approach enables significantly larger and more flexible photonic systems without requiring a proportional increase in hardware complexity.
By combining high-speed operation, exceptional energy efficiency, and scalable programmability on a compact chip, this work establishes a foundation for the next generation of integrated photonic computing platforms. The demonstrated architecture has broad potential for applications in classical and quantum information processing, optical optimization, advanced sensing, and ultrafast signal processing, bringing scalable, light-based computing systems closer to practical deployment.
Visible-to-mid-IR tunable frequency comb in nanophotonics
Authors: Arkadev Roy, Luis Ledezma, Luis Costa, Robert Gray, Ryoto Sekine, Qiushi Guo, Mingchen Liu, Ryan M. Briggs & Alireza Marandi
Publisher: Nature Communications
Executive Summary
Optical frequency combs are a foundational technology for modern photonics, enabling applications ranging from precision metrology and spectroscopy to optical communications, imaging, and high-performance computing. While integrated frequency comb sources have advanced rapidly in recent years, most have been limited to the near-infrared spectrum, leaving the visible and mid-infrared wavelength ranges—which are critical for many scientific and industrial applications—difficult to access with compact, chip-scale devices.
This research demonstrates a major advancement in integrated photonics by developing a widely tunable optical frequency comb source on a single lithium niobate nanophotonic chip. Using an optical parametric oscillator (OPO) architecture combined with dispersion engineering and periodic poling, the device generates coherent frequency combs spanning more than an octave, covering wavelengths from 1.5 μm to 3.3 μm with ultra-low femtojoule-level energy thresholds. In addition, the same chip converts the infrared combs into visible frequency combs reaching wavelengths as short as 620 nm, creating a single integrated platform that spans the visible, near-infrared, and mid-infrared regions.
This broad spectral coverage addresses one of the most significant challenges in integrated photonics: producing efficient, tunable frequency combs outside the near-infrared. By leveraging highly efficient nonlinear optical processes, the demonstrated architecture overcomes the spectral limitations of existing on-chip sources while maintaining compact size, low power consumption, and compatibility with scalable semiconductor manufacturing techniques.
The ability to generate coherent light across such a wide wavelength range on a single chip opens new opportunities for technologies that rely on precise optical measurements. The mid-infrared output aligns with important molecular absorption bands used for chemical analysis and environmental sensing, while the visible spectrum supports applications involving atomic transitions, quantum systems, and precision spectroscopy. Together, this enables a versatile photonic platform capable of serving a broad range of scientific, industrial, and communications applications.
By combining ultra-broadband tunability, exceptional energy efficiency, and multi-wavelength operation in a compact nanophotonic device, this work establishes a practical path toward next-generation integrated frequency comb sources. The demonstrated platform advances the state of integrated nonlinear photonics and lays the foundation for scalable, wafer-manufacturable optical systems that can power future innovations in sensing, communications, precision measurement, and quantum technologies.
Ultrafast neuromorphic computing with nanophotonic optical parametric oscillators
Authors: Midya Parto, Gordon H.Y. Li, Ryoto Sekine, Robert M. Gray, Luis L. Ledezma, James Williams, Arkadev Roy, Alireza Marandi
Publisher: Arxiv
Executive Summary
Artificial intelligence has rapidly transformed industries by enabling machines to recognize patterns, analyze complex data, and make increasingly sophisticated decisions. As AI models continue to grow in size and computational complexity, conventional electronic processors face mounting challenges related to latency, power consumption, and data movement. Photonic computing offers a compelling alternative by using light to perform computations, delivering significantly higher bandwidth and lower energy consumption than traditional electronic architectures. However, a key challenge has been developing integrated photonic systems capable of performing both the linear and nonlinear operations required for neural networks entirely in the optical domain.
This research demonstrates an ultrafast nanophotonic neuromorphic processor built on a thin-film lithium niobate platform that performs AI computations using an optical parametric oscillator (OPO). Rather than relying on electronic processing between computational steps, the architecture uses the nonlinear dynamics of coupled optical pulses to create the internal nodes of a deep recurrent neural network. This entirely optical approach eliminates the optical-electrical-optical (OEO) conversions that have historically limited the speed and efficiency of photonic AI systems.
The demonstrated processor successfully performed several representative machine learning tasks, including chaotic time-series prediction, nonlinear error correction in noisy communication channels, and classification of noisy waveforms. Across these benchmarks, the system achieved classification and prediction accuracies exceeding 93% while operating at an approximately 10 GHz clock rate. Equally important, the processor delivers sub-nanosecond inference latency—comparable to a single clock cycle in today's most advanced digital processors—highlighting its potential for real-time AI applications that demand both speed and energy efficiency.
A key innovation of this work is the use of a compact optical parametric oscillator network to perform nonlinear neural network operations directly with light. This architecture overcomes one of the primary barriers to practical photonic neural networks by integrating computation and memory within a scalable nanophotonic platform. As a result, the processor combines ultrafast operation with the inherent advantages of optical computing, including low propagation losses and exceptionally high bandwidth.
By demonstrating accurate, high-speed neural network inference entirely in the optical domain, this research establishes an important milestone toward practical photonic AI hardware. The demonstrated architecture provides a foundation for next-generation neuromorphic processors capable of supporting edge AI, intelligent communications, scientific computing, and real-time signal processing. As demand for faster and more energy-efficient AI infrastructure continues to accelerate, integrated photonic processors such as this offer a promising path beyond the limitations of conventional electronic computing.