Enhanced acoustic sensitivity through high--resonator mechanical resonance sidebands.

This paper presents a method for high-resolution and high-sensitivity detection of weak acoustic signals based on the mechanical resonance calcium fluoride () resonator. The method utilizes sideband signals generated by the coupling of the frequency of the acoustic signals to be measured and the intrinsic mechanical frequency of the resonator. At a quality factor (-factor) of 1.

Low-Frequency Magnetic Sensing Using Magnetically Modulated Microcavity Resonant Mode.

We propose a low-frequency magnetic sensing method using a magnetically modulated microcavity resonant mode. Our magnetically sensitive unit with periodically changing magnetic poles is formed by combining an AC excitation coil with a microcavity. The microcavity vibrates at the frequency of the AC amplitude-modulated signal and changes its resonant mode when the sensing unit interacts with a low-frequency magnetic field.

Ultra-flat electro-optic frequency comb based on a chirp-modulated lithium niobate resonator.

Chirp modulation can generate a relatively flat electro-optic frequency comb (EO comb) and offers the advantage of frequency reconfigurability, demonstrating significant potential in high-precision sensing and absorption spectroscopy measurements. However, nonresonant devices such as waveguides are susceptible to limitations in modulation efficiency and bandwidth during electro-optic modulation. In this paper, by utilizing chirp modulation resonance mode, we have realized an EO comb based on a lithium niobate resonator with small tooth spacing and high flatness.

Dispersion response broadband tunable underwater FMCW blue chirped laser source.

Frequency-modulated continuous-wave (FMCW) narrow linewidth lasers have served as the cornerstone behind applications such as autonomous driving, wearable technology, virtual reality, and remote sensing mapping. Strongly coherent lasers are typically used for these studies, with a clear demand for linear fast response and wide frequency tuning range. In this paper, profiting from the ultrahigh-quality factor of the crystalline whispering-gallery-mode resonator, by using a self-injection locking mechanism to suppress spontaneous emission noise and improve coherence, sub-kHz linewidth at 450 nm is obtained.

Highly Sensitive Force Sensor Based on High-Q Asymmetric V-Shaped CaF Resonator.

Whispering gallery mode (WGM) resonators have high-quality factors and can be used in high-sensitivity sensors due to the narrow line width that allows for the detection of small external changes. In this paper, a force-sensing system based on a high-Q asymmetric V-shaped CaF resonator is proposed. Based on the dispersion coupling mechanism, the deformation of the resonator is achieved by loading force, and the resonant frequency is changed to determine the measurement.

Towards better predicting the settling velocity of film-shaped microplastics based on experiment and simulation data.

The properties of microplastics determine their settling velocities and affect the fates and migration pathways of microplastics. This paper has simulated the settling velocities of film-shaped microplastics, which are present in natural aquatic environments. The numerical results provided more data to fit the terminal settling velocities of film-shaped microplastics.

High resolution acoustic sensing based on microcavity optomechanical oscillator.

In this paper, a simple sensing method based on a silicon oxide microcavity optomechanical oscillator (OMO) is proposed and demonstrated for the detection of acoustic signals. Firstly, the resonance damping was reduced by improving the optical quality factor (Q) and increasing the sphere-to-neck ratio. After optimizing the process, a microsphere OMO was fabricated, which has an ultra-high mechanical quality factor (6.

Ultra-stable control near the EP in non-Hermitian systems and high-precision angular rate sensing applications.

In non-Hermitian systems, enhancing sensitivity under exceptional point (EP) conditions offers an ideal solution for reconciling the trade-off between sensitivity and size constraints in sensing applications. However, practical application is limited by undesired sensitivity to external fluctuations, noise, and errors in signal amplification synchronization. This paper presents a precisely controlled EP tracking and detection system (EPTDS) that achieves long-term rapid tracking and locking near the EP by constructing a second-order non-Hermitian optical sensing unit, employing an optical power adaptive control method, and utilizing a combinatorial demodulation-based dual-loop cascaded control (CDCC) technique to selectively suppress traditional noise at different frequencies.

Settling processes of cylindrical microplastics in quiescent water: A fully resolved numerical simulation study.

The settling process of marine microplastics (MPs) is crucial research concerning the transport and movement of MPs. The settling processes of MP fibers that possess a cylindrical geometry are affected by environmental factors and properties. In this study, a three-dimensional numerical model for the still water settling of MPs with complex shapes was constructed using the lattice Boltzmann method (LBM) and the immersed boundary method (IBM).

An ultrahigh sensitivity acoustic sensor system for weak signal detection based on an ultrahigh- CaF resonator.

Acoustic sensors with ultrahigh sensitivity, broadband response, and high resolution are essential for high-precision nondestructive weak signal detection technology. In this paper, based on the size effect of an ultrahigh-quality () calcium fluoride (CaF) resonator, a weak acoustic signal is detected by the dispersive response regime in which an acoustic, elastic wave modulates the geometry and is converted to a resonance frequency shift. Through the structural design of the resonator, the sensitivity reaches 11.

Compact on-chip crystalline resonator integration with etching of tapered fiber waveguide.

Whispering-gallery-mode crystalline resonators currently maintain the best quality factor () record; however, compact on-chip packaging is still a challenge, although various coupling architectures have been developed. Here, a chemical etching method is proposed to fabricate a miniaturized tapered fiber waveguide on silicon substrate. The Marangoni effect is implemented to reduce the surface roughness of the cone region.

Sandwich structure magnetometer with a high sensitivity and signal-to-noise ratio based on an ultrahigh-Q CaF resonator.

Whispering gallery mode (WGM) resonators with an ultrahigh quality () factor provide an extremely high resolution for high-precision sensing. However, it is difficult to use them directly in magnetic sensors because of the transparency to the magnetic field. In this paper, a sandwich structure consisting of a neodymium iron boron magnet and calcium fluoride resonator with a factor of 10 is proposed.

Design of an ultra-broadband and low-loss 3 dB power splitter from the 1.25 to 2.04 µm wave band.

As a key component of the beam splitting and combining in photonic integrated circuits, an optical power splitter requires the characteristics of compactness, broadband, and low loss. Here, we propose a 1×2 ultra-broadband 3 dB power splitter with a 5 µm long beam splitting area, based on the structure of a subwavelength grating. The 0.

Large-scale flexible-resonators with temperature insensitivity employing superoleophobic substrates.

Whispering gallery mode polymer resonators are becoming competitive with devices made of other materials, however, the inherent thermal sensitivity of the materials and the small size limit their applications, such as high-precision optical gyroscope. Here, a method is proposed for fabricating large-scale NOA65 resonators with quality factors greater than 10 on a chip employing superoleophobic. The sandwich structure as the core layer of resonator is used to present the flexible remodeling characteristics, the surface roughness remains below 1 nm when the diameter changes by more than 25%.

A High-Sensitivity Resonant Magnetic Sensor Based on Graphene Nanomechanical Resonator.

This paper presents a novel resonant magnetic sensor consisting of a graphene nanomechanical oscillator and magnetostrictive stress coupling structure, using Si/SiO substrate and Fe-Ga alloy, respectively. In this device, the deformation of the Fe-Ga alloy resulting from the external magnetic field changed the surface tension of the graphene, resulting in a significant change in the resonance frequency of graphene. Using the finite element analysis, it could be found that the response of the resonance frequency revealed a good linear relationship with the external magnetic field (along the -axis) in the range of the 1 to 1.

Reducing backscattering and the Kerr noise in a resonant micro-optic gyro using two independent lasers.

In a resonator micro-optic gyroscope (R-MOG), backscattering noise and Kerr noise have been key issues affecting the optical gyro output that are difficult to completely suppress. A method is proposed to suppress backscattering noise in a R-MOG. It uses two independent lasers and, by locking the two optical signals at different resonance peaks, a differential output of the two optical signals is achieved that successfully suppresses the backscattering noise.

Time delay effect in a microchip pulse laser for the nonlinear photoacoustic signal enhancement.

The Grüneisen relaxation effect has been successfully employed to improve the photoacoustic (PA) imaging contrast. However, complex system design and cost hinder the progress from benchside to bedside, since an additional pre-heating laser source needs to be coupled into the original light path and synchronized with other equipment for conducting the nonlinear effect. To overcome the limitation, we propose a time delay heating PA imaging (TDH-PAI) method based on the time delay effect in a passively Q-switched laser.

Dynamically tunable multi-lobe laser generation via multifocal curved beam.

Beams with curved properties, represented by Airy beam, have already shown potential applications in various fields. Here we propose a simple method to achieve a multifocal curved beam (MCB). The scheme is based on the ability of microspheres to control the distribution of the light field.

Low lateral divergence 2 μm InGaSb/ AlGaAsSb broad-area quantum well lasers.

High power and high brightness mid-infrared GaSb based lasers are desired for many applications, however, the high lateral divergence is still the influence factor for practical application. In this paper, a simple and effective approach based on the fishbone-shape microstructure was proposed, the effective improvement on both the lateral divergence and output power of 2 μm GaSb based broad-area lasers was demonstrated. The lateral divergence is reduced averagely by 55% and 15.