arXiv subjects

Yuping Chen

Publications and source records attributed to Yuping Chen.

At least 19 recordsLinked to original sources

arXiv2026

Raman-Assisted Multiband Nonlinear Frequency-Conversion Network in a High-Q LTOI Microdisk

On-chip nonlinear frequency conversion offers a key route to broadband coherent light sources, but spanning telecom, visible, and ultraviolet wavelengths within a single resonator remains challenging. Lithium tantalate-on-insulator (LTOI), which has recently emerged as a promising material platform for integrated photonics, combines strong Raman activity, a large second-order nonlinearity, broad optical transparency and high resistance to photorefractive damage, thereby attracting increasing attention for on-chip nonlinear frequency conversion. Here, we experimentally demonstrate a Raman-assisted multiband frequency-conversion network in a high-Q LTOI microdisk with a loaded quality factor of 2.48x10^6. The resonant pumping produced high-purity single-mode Raman lasing with a 3.14 mW threshold, 32.44% slope efficiency, and an excellent side-mode suppression ratio (SMSR) of 29.5 dB. Under a nearby pump condition, we also observe multiple Stokes components together with an anti-Stokes line on the short-wavelength side of the pump. The resulting multiple intracavity Stokes fields subsequently acted as frequency seeds for cascaded chi^(2) processes, producing near-infrared and visible signals and extending the emission to 312.6 nm in the ultraviolet. These findings establish the cooperative action of Raman gain and second-order nonlinearity across widely separated spectral bands within a single microcavity. The device therefore offers a route toward integrated multiband light sources and a platform for studying coupled nonlinear dynamics.

physics.optics↗

arXiv2026

Thermodynamic Limits on Reliable Signaling by Biochemical Traveling Waves

Biochemical traveling waves transmit signals across cells and tissues, but the thermodynamic cost of reliable propagation remains unclear. We develop a stochastic thermodynamic framework for reaction--diffusion systems with stable traveling waves and show that diffusion of the wave position is bounded by the dissipation specifically associated with propagation. The bound follows by projecting noisy field dynamics onto the adjoint translational mode, which maps the wave position to an effective biased random walk. Its tightness is controlled by the non-self-adjoint part of the linearized dynamics, with finite wave speed and antisymmetric reaction dynamics generically producing deviations from equality. For excitable trigger waves in a FitzHugh--Nagumo model, we show that the slow inhibitor dominates the propagation cost, yielding a trade-off among wave speed, inhibitor amplitude, and dissipation. We test these predictions in stochastic simulations of a microscopic Belousov--Zhabotinsky reaction--diffusion system and find consistent signatures in mitotic trigger-wave experiments in \textit{Xenopus} egg extracts. The same relation further imposes an annihilation-limited bound on the reliable signaling rate of wave trains.

physics.bio-ph↗

arXiv2026

On-Chip Neodymium-Doped Lithium Niobate Microdisk Laser with Self-Induced Pulsing

Rare-earth-doped materials constitute the foundation of conventional solid-state lasers, but their bulk-crystal form is inherently incompatible with photonic integration, making it challenging to realize compact, high performance nanoscale laser sources. Lithium niobate on insulator (LNOI), with its exceptional electro-optic and nonlinear optical properties, has emerged as one of the most promising platforms for integrated photonics. Combining Nd3+ doping with LNOI offers the unique possibility of uniting the efficient gain provided by Nd3+ ions with the excellent characteristics of LNOI. However, on-chip laser emission from Nd:LNOI has not been demonstrated previously. In this work, we report the first realization of an integrated Nd:LNOI microdisk laser, demonstrating lasing at 1094.17 nm under 785.10 nm pumping with a low threshold of 146 uW and a slope efficiency of 1.962*10^(-5). Beyond continuous-wave operation, we further observe self-induced laser pulsing on the hundred-microsecond scale, with a laser-pulse duration down to 500 us and an oscillation period of 6.45 ms, arising from nonlinear thermo-optic-photorefractive dynamics. We demonstrate stable continuous wave lasing and self-induced pulsed emission within a monolithically integrated Nd:LNOI cavity. Our results expand the operational degrees of freedom for LNOI-based lasers and open a new direction toward deeply integrated gain with intrinsic nonlinear dynamical processes.

physics.optics↗

arXiv2025

Erbium-doped lithium niobate waveguide amplifier enhanced by an inverse-designed on-chip reflector

This study presents a 3.6-cm-long erbium-doped lithium niobate waveguide amplifier enhanced by an inverse-designed on-chip reflector. Integrating the reflector at the waveguide end yielded an internal net gain of 40.5 dB, achieving a 17.3 dB gain improvement compared to a comparable reflector-free amplifier under small signal conditions. By eliminating bidirectional pumping requirements, the system complexity was reduced. These results highlight a novel strategy for optimizing integrated optical amplifiers, combining high gain with simplified architecture. The approach holds promise for advancing high-density photonic integrated systems, demonstrating the efficacy of inverse design in tailoring photonic device performance for practical applications.

physics.optics↗

arXiv2024

3D Orbital Angular Momentum Nonlinear Holography

Orbital angular momentum (OAM), due to its theoretically orthogonal and unbounded helical phase index, has been utilized as an independent physical degree of freedom for ultrahigh-capacity information encryption. However, the imaging distance of an OAM hologram is typically inflexible and determined by the focal length of the Fourier transform lens placed behind the hologram. Here, 3D orbital angular momentum holography is proposed and implemented. The Fourier transform between the holographic plane and imaging plane is performed by superimposing Fresnel zone plates (FZP) onto the computer-generated holograms (CGH). The CGH is binarized and fabricated on the birefringence lithium niobate crystal by femtosecond laser micromachining. Experimental verification demonstrates the feasibility of the encoding method. Moreover, by superimposing FZPs with different focal lengths into various OAM channels, OAM-multiplexing holograms are constructed. Target images are separately projected to different planes, thereby enabling 3D multi-plane holographic imaging with low crosstalk. The interval between adjacent imaging planes can be uniform and minimal, free from depth of field constraints, thus achieving high longitudinal resolution. This work achieves OAM holography in a more compact manner and further expands its applicability.

physics.optics↗

arXiv2024

Cascaded multi-phonon stimulated Raman scattering near second-harmonic-generation in thin-film lithium niobate microdisk

High-quality microresonators can greatly enhance light-matter interactions and are excellent platforms for studying nonlinear optics. Wavelength conversion through nonlinear processes is the key to many applications of integrated optics. The stimulated Raman scattering process can extend the emission wavelength of a laser source to a wider range. Lithium niobate, as a Raman active crystalline material, has remarkable potential for wavelength conversion. Here, we demonstrate the generation of cascaded multi-phonon Raman signals near the second-harmonic-generation peak in X-cut thin-film lithium niobate microdisk. Fine tuning of the specific cascaded Raman spectral lines has also been made by changing the pump wavelength. Raman lines can reach wavelength up to about 80 nm away from the SHG signal. We realize the SFG process associated with Raman signals in the visible range as well. Our work extends the use of WGM microresonators as effective optical upconversion wavelength converters in nonlinear optical applications.

physics.optics↗

arXiv2024

Enhanced Nonlinear Frequency Conversion Bandwidth through Birefringence induced Mode Hybridization

On-chip quantum information network requires qubit transfer between different wavelengths while preserving quantum coherence and entanglement, which needs broadband up-conversion available. Herein, we demonstrate a mode-hybridization based broadband nonlinear frequency conversion on X-cut thin film lithium niobate. With the spontaneous quasi-phase matching and quasi groupvelocity matching being simultaneously satisfied, broadband second harmonic generation with a 3-dB bandwidth up to 13 nm has been achieved in a micro-racetrack resonator. The same mechanism can work on the frequency conversion of the ultra-short pulse in the bent waveguide structure. This work will be beneficial to on-chip tunable frequency conversion and quantum light source generation on integrated photonic platforms, and further enable on-chip large-capacity multiplexing, multichannel optical information processing, and large quantum information networks.

physics.optics↗

arXiv2024

Hybrid thin-film lithium niobate micro-ring acousto-optic modulator for microwave-to-optical conversion

Highly efficient acousto-optic modulation plays a vital role in the microwave-to-optical conversion. Herein, we demonstrate a hybrid thin-film lithium niobate (TFLN) racetrack micro-ring acousto-optic modulator (AOM) implemented with low-loss chalcogenide (ChG) waveguide. By engineering the electrode configuration of the interdigital transducer, the double-arm micro-ring acousto-optic modulation is experimentally confirmed in nonsuspended ChG loaded TFLN waveguide platform. Varying the position of blue-detuned bias point, the half-wave-voltage-length product VpaiL of the hybrid TFLN micro-ring AOM is as small as 9 mVcm. Accordingly, the acousto-optic coupling strength is estimated to be 0.48 Hz s1/2 at acoustic frequency of 0.84 GHz. By analyzing the generation of phonon number from the piezoelectric transducer, the microwave-to-optical conversion efficiency is calculated to be 0.05%, approximately one order of magnitude larger than that of the state-of-the-art suspended counterpart. Efficient microwave-to-optical conversion thus provides new opportunities for low-power-consumption quantum information transduction using the TFLN-ChG hybrid piezo-optomechanical devices.

physics.optics↗

arXiv2023

On-chip Lithium Niobate Heterogeneous Photonic Crystal Nanocavity Laser

Thin film lithium niobate (TFLN) has become an platform for modern integrated circuits due to its excellent optical properties. With the development of rare earth ion doped TFLN, important breakthroughs of on-chip microlasers has emerged and show significant application for optical communication, computing and quantum photonics. However, challenges still remain in developing compact lasers with small mode volumes and low threshold on rare earth ion doped TFLN for highly efficient dense integration. In this letter, we fabricated a heterogeneous photonic crystal (PhC) nanobeam cavity on erbium-doped TFLN with a quality factor of 1.2\times10^4 and firstly demonstrated a single-mode integrated PhC laser with submicron mode volume on TFLN platform. Laser at 1559.63 nm is achieved with the 974 nm single-mode pump. The effective mode volume is 1.44 (λ/n)^3 (~ 0.645 μm^3) and the threshold power is 163 μW. Enhanced photorefractive effect in the PhC cavity is measured. This lithium niobate photonic crystal nanocavity laser, as a compact telecommunication C-band on-chip light source, would benefit the progress of high-speed and low-cost optical community on TFLN integrated photonics.

physics.optics↗

arXiv2023

Self-Amplification-Assisted Highly Efficient Integrated Laser

Light source is indispensable component in on-chip system. Compared with hybrid or heterogeneous integrated laser, monolithically integrated laser is more suitable for high density photonic integrated circuit (PIC) since the capability of large-scale manufacturing, lower active-passive coupling loss and less test complexity. Recent years have seen the spark of researches on rare-earth ion doped thin film lithium niobate (REI:TFLN), demonstrations have been made both in classical and quantum chips. However, low output power and limited quantum emitting efficiency hinder the application of the chip-scale laser source based on REI:TFLN. Here a highly efficient integrated laser assisted by cascaded amplifiers is proposed and experimentally prepared on Erbium-doped TFLN. A slope efficiency of 0.43% and a linewidth of 47.86 kHz are obtained. The maximum integrated laser power is 7.989 μW. Our results show a viable solution to improve efficiency by self-amplification without changing the intrinsic quantum emitting efficiency of the material, and our design has potential application in incorporating with functional devices such as optical communications, integrated quantum memory and quantum emission.

physics.optics↗

arXiv2023

Enhanced temperature sensing by multi-mode coupling in an on-chip microcavity system

The micro-cavity is a promising sensor platform, any perturbation would disturb its linewidth, cause resonance shift or splitting. However, such sensing resolution is limited by the cavity's optical quality factor and mode volume. Here we propose and demonstrate in an on-chip integrated microcavity system that resolution of a self referenced sensor could be enhanced with multi mode coupling.

physics.optics↗

arXiv2022

Simultaneous $ χ^{(2)} $- $ χ^{(2)} $ and $ χ^{(2)} $-$ χ^{(3)} $ nonlinear processes generation in thin film lithium tantalate microcavity

On-chip efficient nonlinear functions are instrumental in escalating the utilities and performance of photonic integrated circuits (PICs), especially for a wide range of classical and quantum applications, such as tunable coherent radiation, optical frequency conversion, spectroscopy, quantum science, etc. Lithium tantalate (LT) has been widely used in nonlinear wavelength converters, surface acoustic wave resonators, and electro-optic, acoustic-optic devices owing to its excellent optical properties. Here, we fabricated a Z-cut lithium tantalate on insulator (LTOI) microdisk with high quality(Q) factors in both telecom (10$^{6}$) and visible (10$^{5}$) bands by optimizing the fabrication. With the Q factor of the LTOI microdisk increasing, we can obtain higher pump light intensity in the cavity which is beneficial to get more optical nonlinear effect easily. By making use of the mode phase matching of interacting waves and inputting high pump power, we experimentally observed on-chip near-infrared light, visible (red, green), and ultraviolet (UV) from microresonator-based $ χ^{(2)}-χ^{(2)}$, $ χ^{(2)}-χ^{(3)}$, and $χ^{(2)}$ nonlinear processes such as cascaded four-wave mixing (cFWM), cascaded sum-frequency generation (cSFG), third harmonic generation (THG), second harmonic generation (SHG). It is believed that the LTOI can support a variety of on-chip optical nonlinear processes, which heralds its new application potential in integrated nonlinear photonics.

physics.optics↗

arXiv2022

Doubly resonant photonic crystal cavity using merged bound states in the continuum

In this work, a doubly resonant photonic crystal (PhC) cavity using the merged bound states in the continuum (BICs) is proposed to obtain a higher second harmonic generation (SHG) efficiency. Firstly by scanning geometry parameters the accidental BICs and a band-edge mode outside the light cone can be obtained. Then as the lattice constant or the thickness of the slab is adjusted the accidental BICs will merge. A supercell with large and small holes is constructed and the band-edge mode outside the light cone can be mode-matched with the merged BICs mode. Finally the heterostructure PhC cavity is designed. The merged BICs show a high quality factor for the photonic crystal with finite size. Consequently, the SHG efficiency of the lattice constant near merged BICs of ~6000% W-1 is higher than the one of the isolated BIC.

physics.optics↗

arXiv2022

Large Quality Factor Enhancement Based on Cascaded Uniform Lithium Niobate Bichromatic Photonic Crystal Cavities

In this paper, by cascading several bichromatic photonic crystals we demonstrate that the quality factor can be much larger compared with that in an isolated cavity without increasing the total size of the device. We take lithium niobate photonic crystal as an example to illustrate that the simulated quality factor of the cascaded cavity can attain 10^5 with a 70° slant angle, which is an order of magnitude larger than that in isolated cavity. The device can be fabricated easily by current etching technique for lithium niobate. We have fabricated the proposed device experimentally including holes with 70° slant angle. This work is expected to provide guidance to the design of photonic crystal cavity with high-quality factor.

physics.optics↗

arXiv2022

Chip-scale Spontaneous Quasi-Phase-Matched Micro-Racetrack Resonator

Due to their capacity for non-classical light generation, high-efficiency second-order nonlinear parametric processes play an important role in quantum photonic technology, and chip-scale realization of these processes is recognized as the key to building efficient light sources for integrated quantum photonic circuits. To achieve ultra-high nonlinear conversion efficiency, traditional method uses quasi-phase matching (QPM) technology. However, QPM requires electric field poling, which is incompatible with the CMOS fabrication process, and this hinders the wafer-scale production of integrated photonic circuits. In this paper, we demonstrate efficient spontaneous quasi-phase matched (SQPM) frequency conversion in a micro-racetrack resonator. Our approach does not involve poling, but exploits the anisotropy of the ferroelectric crystals to allow the phase-matching condition to be fulfilled spontaneously as the TE-polarized light circulates in a specifically designed racetrack resonator. SQPM second harmonic generation is observed with a normalized intracavity conversion efficiency of 0.85%/W, corresponding to the 111st-order QPM. This could theoretically reach 186,000%/W by first-order QPM. In this case such high intracavity conversion efficiency can be implemented in practice with an optimized outward coupling. Our configurable SQPM approach will benefit the application of nonlinear frequency conversion in chip-scale integrated photonics with CMOS-compatible fabrication processes, and is applicable to other on-chip nonlinear processes such as quantum frequency conversion or frequency-comb generation.

physics.optics↗

arXiv2021

Tunable single-mode laser on thin film lithium niobate

Erbium-doped lithium niobate on insulator (LNOI) laser plays an important role in the complete photonic integrated circuits (PICs). Here, we demonstrate an integrated tunable whisper galley single mode laser (WGSML) by making use of a pair of coupled microdisk and microring on LNOI. A 974 nm single-mode pump light can have an excellent resonance in the designed microdisk, which is beneficial to the whisper gallery mode (WGM) laser generation. The WGSML at 1560.40 nm with a maximum 31.4 dB side mode suppression ratio (SMSR) has been achieved. By regulating the temperature, WGSMLs output power increased and the central wavelength can be changed from 1560.30 nm to 1560.40 nm. What's more, 1560.60 nm and 1565.00 nm WGSMLs have been achieved by changing the coupling gap width between microdisk and microring. We can also use the electro-optic effect of LNOI to obtain more accurate adjustable WGSMLs in further research.

physics.optics↗

arXiv2021

Integrated spiral waveguide amplifiers on erbium-doped thin-film lithium niobate

Integrated optical amplifiers and light sources are of great significance for photonic integrated circuits (PICs) and have attracted many research interests. Doping rare-earth ions in materials as a solution to realize efficient optical amplifiers and lasing has been investigated a lot. We investigate the erbium-doped lithium niobate on insulator (LNOI). Here, spiral waveguide amplifiers were fabricated on a 1-mol\% erbium-doped LNOI by CMOS-compatible technique. We demonstrated a maximum internal net gain of 8.3 dB at 1530 nm indicating a net gain per unit length of 15.6 dB/cm with a compact spiral waveguide of 5.3 mm length and $ \sim $0.06 mm$ ^{2} $ footprint. The erbium-doped integrated lithium niobate spiral waveguide amplifiers would pave the way in the PICs of the lithium niobate platform, especially in achieving efficient integration of active and passive devices on a lithium niobate thin film, which will make full use of its excellent physical properties such as remarkable photoacoustic, electro-optic, and piezoelectric characteristics.

physics.optics↗

arXiv2020

On-chip Erbium-doped lithium niobate microcavity laser

The commercialization of lithium niobate on insulator (LNOI) wafer has sparked significant on-chip photonic integration application due to its remarkable photonic, photoacoustic, electro-optic and piezoelectric nature. A variety of on-chip LNOI-based optical devices with high performance has been realized in recent years. Here we developed 1 mol\% erbium-doped LN crystal and its LNOI wafer, and fabricated an erbium-doped LNOI microdisk with high quality ($ \sim $ 1.05$\times 10^{^5}$ ). C-band laser emission with $ \sim $1530 nm and $ \sim $1560 nm from the high-Q erbium-doped LNOI microdisk was demonstrated both with 974 nm and 1460 nm pumping, and the latter has better thermal stability. This microlaser would play an important role in the photonic integrated circuits of lithium niobate platform.

physics.optics↗