
- Apr. 16, 2025
- Vol. , Issue (2025)
- Apr. 16, 2025
- Vol. , Issue (2025)
- Apr. 15, 2025
- Vol. 2, Issue 1 (2025)
- Apr. 10, 2025
- Vol. , Issue (2025)
- Apr. 10, 2025
- Vol. , Issue (2025)
In laser systems requiring a flat-top distribution of beam intensity, beam smoothing is a critical technology for enhancing laser energy deposition onto t
In laser systems requiring a flat-top distribution of beam intensity, beam smoothing is a critical technology for enhancing laser energy deposition onto the focal spot. The continuous phase modulator (CPM) is a key component in beam smoothing, as it introduces high-frequency continuous phase modulation across the laser beam profile. However, the presence of the CPM makes it challenging to measure and correct the wavefront aberration of the input laser beam effectively, leading to unwanted beam intensity distribution and bringing difficulty to the design of the CPM. To address this issue, we propose a deep learning enabled robust wavefront sensing (DLWS) method to achieve effective wavefront measurement and active aberration correction, thereby facilitating active beam smoothing using the CPM. The experimental results show that the average wavefront reconstruction error of the DLWS method is 0.04 μm in the root mean square, while the Shack–Hartmann wavefront sensor reconstruction error is 0.17 μm.show less
- Apr.18,2025
- High Power Laser Science and Engineering,Vol. 13, Issue 2
- 02000e19 (2025)
We propose a fast-printable and function-switchable metamaterial based on laser-induced graphene for terahertz (THz) wave modulation in the reflection mod
We propose a fast-printable and function-switchable metamaterial based on laser-induced graphene for terahertz (THz) wave modulation in the reflection mode. The design can modulate the linear polarization of the incoming wave fronts to its cross-polarization from 0.27 to 0.41 THz and linear polarization to circular polarization from 0.48 to 0.62 THz. The function of the device can also be switched from a polarization converter to an absorber by bending it with an angle of 57°. Experimental results showed a good agreement with those of the simulation. The proposed polarization converter may find its application in THz polarization control systems and sensing.show less
- Apr.18,2025
- Chinese Optics Letters,Vol. 23, Issue 4
- 043603 (2025)
- Apr.18,2025
- Advanced Imaging,Vol. 2, Issue 2
- 023001 (2025)
The femtosecond laser direct writing technique is a highly precise processing method that enables the rapid fabrication of three-dimensional (3D) micro- a
The femtosecond laser direct writing technique is a highly precise processing method that enables the rapid fabrication of three-dimensional (3D) micro- and nanoscale photonic structures in transparent materials. By focusing ultrashort laser pulses into transparent optical materials, such as crystals and glasses, it is possible to efficiently modify specific optical properties, including refractive indices and ferroelectric domains, at the laser focus. By carefully designing and optimizing the movement trajectory of the femtosecond laser, one can achieve periodic modulation of the optical features of these materials in 3D space. The resulting changes in material properties are closely linked to both the processing parameters of the femtosecond laser and the types of materials used. Through ongoing optimization of these parameters, desired periodic photonic structures can be created in specific transparent optical materials, leading to the development of 3D nonlinear photonic crystals (NPCs) and 3D waveguide arrays. Femtosecond laser direct writing breaks through the limitations of traditional techniques to fabricate 3D NPCs [e.g., 3D lithium niobate (LiNbO3) NPCs] and complex waveguide arrays (e.g., 3D helical waveguide arrays), realizing a paradigm shift in the fabrication of complex periodic photonic structures. To date, femtosecond-laser-written 3D NPCs and waveguide arrays have found extensive applications in integrated photonics, nonlinear optics, quantum optics, and topological photonics. We highlight recent advancements in femtosecond-laser-written 3D NPCs and waveguide arrays, such as pivotal breakthroughs in the fabrication of nanoscale-resolution 3D NPCs in LiNbO3. Finally, several potential research directions, such as the formation mechanism of domain wall and inducing millimeter-scale domain inversion with femtosecond Bessel beam, have been proposed at the end of this article.show less
- Apr.16,2025
- Advanced Photonics,Vol. 7, Issue 3
- 034002 (2025)
A dual-beam platform is developed for all-optical Thomson/Compton scattering, with versatile parameter tuning capabilities including electron energy, radiation energy, radiation polarization, et
A dual-beam platform is developed for all-optical Thomson/Compton scattering, with versatile parameter tuning capabilities including electron energy, radiation energy, radiation polarization, etc. By integrating this platform with a 200 TW Ti: Sapphire laser system, we demonstrate the generation of inverse Compton scattering X/gamma-rays with tunable energies ranging from tens of keV to MeV. The polarization of X/gamma-rays is manipulated by adjusting the polarization of the scattering laser. In the near future, by combining this platform with multi-PW laser facilities, our goal is to explore the transition from nonlinear Thomson scattering to nonlinear Compton scattering, ultimately verifying theories related to strong-field quantum electrodynamics effects induced by extreme scattering.show less
- Apr.18,2025
- High Power Laser Science and Engineering
Fiber-coupled laser pumps with Size,Weight and Power consumption(Swap) become more and more compelling for applications in both industrial and defense applications. This study presents an innova
Fiber-coupled laser pumps with Size,Weight and Power consumption(Swap) become more and more compelling for applications in both industrial and defense applications. This study presents an innovative approach employing spectral beam combining (SBC) technique and double-junction laser diode chips to create efficient, high-power,high-brightness f iber-coupled packages. We successfully demonstrate a wavelength-stabilized pump module capable of delivering over 560 W of ex-fiber power with an electro-optical conversion efficienc(PCE) of 55 % from a 135 µm diameter, 0.22NA f iber. The specific mass and volume metrics achieved are 0.34 kg/kW and 0.23 cm3/W, respectively. The module exhibits a consistent spectral peak interval of approximately 3.6 nm and a full width at half maximum (FWHM) across a wide range of operating currents.show less
- Apr.18,2025
- High Power Laser Science and Engineering
Optical neural networks have emerged as feasible alternatives to their electronic counterparts, offering significant benefits such as low power consumption, low latency, and high parallelism. Ho
Optical neural networks have emerged as feasible alternatives to their electronic counterparts, offering significant benefits such as low power consumption, low latency, and high parallelism. However, the realization of ultra-compact nonlinear deep neural network and multi-thread processing remain crucial challenge for optical computing. Here, we present a monolithically integrated all-optical nonlinear diffractive deep neural network (AON-D2NN) chip for the first time. The all-optical nonlinear activation function is implemented using germanium microstructures, which provide low loss and are compatible with the standard silicon photonics fabrication process. Assisted by the germanium activation function, the classification accuracy is improved by 9.1% for four-classification tasks. Additionally, the chip’s reconfigurability enables multi-task learning in-situ via an innovative cross-training algorithm, yielding two task-specific inference results with accuracies of 95% and 96%, respectively. Furthermore, leveraging the wavelength-dependent response of chip, the multi-thread nonlinear optical neural network is implemented for the first time, capable of handling two different tasks in parallel. The proposed AON-D2NN contains three hidden layers with a footprint of only 0.73 mm2. It can achieve ultra-low latency (172 ps), paving the path for realizing high-performance optical neural networks.show less
- Apr.17,2025
- Advanced Photonics,Vol. 7, Issue 4
- (2025)
We propose and demonstrate experimentally a tunable filter based on Mach-Zehnder interference (MZI) assisted micro-ring resonator (MRR) formed on lithium niobate on insulator (LNOI) platform. Ou
We propose and demonstrate experimentally a tunable filter based on Mach-Zehnder interference (MZI) assisted micro-ring resonator (MRR) formed on lithium niobate on insulator (LNOI) platform. Our proposed filter can achieve electro-optic (EO) and thermo-optic (TO) tuning for the bandwidth and the dip wavelength simultaneously. Our typically fabricated filter shows that the minimum and maximum 3-dB bandwidths at Through Port are 27.86 GHz and 31.74 GHz, respectively, while at Drop Port, these values are 14.68 GHz and 30.69 GHz. Meanwhile, the TO and EO tuning rates of the dip wavelength are approximately −6.5 pm/mW and −65.09 pm/V, respectively. Our proposed filter has the potential to be used in optical communication and optical information processing systems to achieve multifunctional filtering characteristics.show less
- Apr.17,2025
- Chinese Optics Letters,Vol. 23, Issue 8
- (2025)