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- 摘要
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- 实验方案
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Simultaneous Generation of Complex Structured Curve Beam
摘要： At present, people are using holographic technologies to shape complex optical beams for both fundamental research and practical applications. However, most of the reported works are focusing on the generation of a single beam pattern based on the computer-generated hologram (CGH). In this paper, we present a method for simultaneously shaping the multiple beam lattice where the intensity and phase of each individual beam can be prescribed along an arbitrary geometric curve. The CGH that is responsible for each individual beam is calculated by using the holographic beam shaping technique, afterwards all the CGHs are multiplexed and encoded into one phase-only hologram by adding respective linear phase grating such that different curves are appeared in different positions of the focal regions. We experimentally prove that the simultaneous generation of multiple beams can be readily achieved. The generated beams are especially useful for applications such as multitasking micro-machining and optical trapping.
关键词： computer holography,beam shaping,spatial light modulation
更新于2025-09-23 15:22:29
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Flexibly adjustable depth-of-focus photoacoustic microscopy with spatial light modulation
摘要： Through focusing the excitation laser, optical-resolution photoacoustic microscopy (OR-PAM) is capable of measuring optical absorption properties down to micrometer-scale lateral resolution within biological tissues. The focused Gaussian beam routinely employed in the OR-PAM setups is inadequate for acquiring the volumetric images of biological specimens with thickness from tens micrometers to millimeter without scanning in depth because of the inconsistent lateral resolution along the depth direction due to its short depth of focus (DoF). Here, we integrate a spatial light modulator (SLM) into the optical path of an OR-PAM for realizing the flexibly adjustable DoF. By simply switching the phase patterns assigned onto the SLM interface, three representative illumination beams are produced, including conventional short-DoF Gaussian beam (GB), needle-like Bessel beam (BB), and extended depth-of-focus beam (EDFB). These modulations can be well realized based on the extended Nijboer-Zernike theory. The photoacoustic excitations show variable DoFs ranging from hundreds of micrometers (GB and BB) up to 1.38 mm (EDFB) but a consistent lateral resolution of (cid:2)3.5 lm. The proposed method is confirmed by volumetric imaging of multiple tungsten fibers positioned at different depths.
关键词： spatial light modulation,photoacoustic microscopy,depth-of-focus,extended depth-of-focus beam,Bessel beam,optical-resolution
更新于2025-09-23 15:21:21
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Optically Modulated Threshold Switching in Corea??Shell Quantum Dot Based Memristive Device
摘要： The threshold switching (TS) phenomenon in memristors has drawn great attention for its versatile applications in selectors, artificial neurons, true random number generators, and electronic integrations. The transition between nonvolatile resistive switching and volatile TS modes can be realized by doping, varying annealing and voltage sweeping conditions, or imposing different compliance current. Here, a strategy is reported to achieve such transition by the noninvasive UV light stimulus based on InP/ZnS quantum dot (QD) memristor. The core–shell InP/ZnS QDs with quasi-type II band alignment ensures photoexcited electrons localized in InP core, photoexcited hole state distributed in the outer shell, and subsequent lifetime controlling of conductive filament under light irradiation. Systematic mechanism investigations indicate that UV photogenerated holes are accumulated on the surface of the QD film, which is consistent with rapid transfer of photogenerated holes in the core–shell InP/ZnS structure. Based on the light-modulated effect, a reconfigurable 9 × 9 visual data storage array with a key pattern and a simple leaky integrate-and-fire circuit are constructed. These results suggest the potential of direct optical modulation of memory mode through energy band engineering, leading to future optoelectronic and electronic device for the implementation of neuromorphic visual system and artificial neural networks.
关键词： quantum dots,light modulation,volatile threshold switching
更新于2025-09-23 15:19:57
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Mid‐Infrared Photonics Using 2D Materials: Status and Challenges
摘要： In recent years, a variety of 2-dimensional (2D) materials including graphene, topological insulators, transition metal dichalcogenides, and black phosphorus have been utilized in photonics and optoelectronics applications. Since the mid-infrared (MIR) region has a significant role in various fields, rapid progress has been made on photonics and optoelectronics applications using 2D materials. Herein, the progress in the photonics devices that exploit the unique properties of 2D materials for a range of MIR applications is summarized, focusing on ultrafast light generation, MIR light modulation, and photodetection. By taking advantage of ultrafast light response, broadband absorption, and high carrier mobility of 2D materials, femtosecond lasers, broadband optical modulators, and high-responsivity photodetectors are achieved. Some perspectives on 2D material-based MIR photonics are highlighted. Due to their MIR bandgaps, small size, high carrier mobility, and easy integration, 2D materials are appealing for MIR photonics applications. Moreover, the availability of an increasingly broad library of 2D materials with variable electronic and optical properties, and the ability to be thinned and restacked into functional and complex assembled structures, enable the development of a highly integrated MIR photonic chip, which will make information technology greener, faster, and lower in energy consumption.
关键词： light modulation,photodetection,mid-infrared,2D materials
更新于2025-09-12 10:27:22
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Electrochromic Infrared Light Modulation in Optical Waveguides
摘要： Electrochromic materials and devices have attracted much attention with their ability to tune the transmissions of visible to infrared (IR) light, allowing the creation of smart windows. This study presents a novel electrochromic device (ECD)-based photonic device that can modulate IR light intensity in a planar optical waveguide ECD. To configure it, a multilayer ECD made of WO3 is integrated on a polymer optical waveguide platform. By using the waveguide to change the optical properties of the ECD electrically, IR light propagating along the optical waveguide core undergoes electroabsorption loss due to the change in charge carrier density in WO3 layer and its intensity is modulated with an extinction depth of 0.6 dB mm?1. Experimental results show that the device is capable of discrete intensity attenuation by applying a distinct level gate voltage. Periodic application of gate voltage leads the device to serve as an optical modulator on the order of subseconds. The results also confirm that a new approach to consider ECD-based optical modulators can pave the way for the development of planar photonic-integrated circuits and systems.
关键词： infrared light modulation,optical waveguides,electrochromic devices
更新于2025-09-12 10:27:22