Visualization 1: Generation of stochastic electromagnetic beams with complete controllable coherence

Dynamic pattern with modulation magnitude 0.5 Originally published in Optics Express on 19 September 2016 (oe-24-19-21587

Visualization 1: Tight focusing of femtosecond radially polarized light pulses through a dielectric interface

The propagation evolution of the radially polarized, ultrashort pulsed laser beams. Originally published in JOSA A on 01 September 2015 (josaa-32-9-1717

Dual-comb-enhanced microwave clock synchronization over commercial fiber

The large-scale clock network is the key ingredient to obtain high precision in many scenarios, from fundamental research to cutting-edge applications. However, time synchronization among microwave clocks has become an upper limit of the time-frequency network because of the inherent constrained precision in optical pulse measurements. Here, we demonstrate a femtosecond-level time synchronization of microwave clocks through a commercial link of 205.86 km via dual-comb-enhanced optical two-way time transfer, which achieves a 6.23-fs residual time deviation between synchronized timescales at 1 s and an instability below 6E-18 at 10,000 s. Further, the high-precision time synchronization of microwave clocks significantly enhances the probe ability of subtle reciprocity changes of fiber to the sub-picosecond level. This work provides a path toward secure fiber time-frequency networks to support future microwave-clock-based precise timing and sensing systems

Single-shot recognition of orbital angular momentum from speckles with spatially multiplexed point detection (SMPD)

The widely adopted optical information detection strategies nowadays can be roughly classified into spatial-resolve-based and time-sequence-based methods. The former is highly reliant on detectors with spatial resolution that works in a limited spectrum range to capture the intensity distribution of the object, whereas the latter employs single-pixel detectors (SPDs) with improved reliability and stability in detection at the expense of time consumption due to sequential intensity recording. However, there is a scarcity of research on using high-performance SPDs for single-shot object information detection. To capture and extract features of objects efficiently and economically, in this work, we propose a single-shot optical information-detecting method, tentatively named spatially multiplexed point detection (SMPD) technology, in which some SPDs are randomly distributed at different locations to acquire the information of the object. To validate the validity of the proposed method, we demonstrate high-fidelity recognition of orbital angular momentum (OAM) modes from speckle patterns generated by the transmission of two orthogonally polarized vortex beams through a multimode fiber. It is feasible to apply this approach in wide applications, such as image transmission based on multiplexed-OAM decoding and recognizing hand-written digits. Compared with traditional image recognition methods, the new approach yields a recognition accuracy of over 98% with an effective detection area that is only 0.02% of its counterparts. With further engineering, the proposed method may spur many exciting developments in OAM-based optical communication systems, image classification, object detections, and other optical information detections

Optical Microfiber Intelligent Sensor: Wearable Cardiorespiratory and Behavior Monitoring with a Flexible Wave-Shaped Polymer Optical Microfiber

With the advantages of high flexibility, strong real-time monitoring capabilities, and convenience, wearable devices have shown increasingly powerful application potential in medical rehabilitation, health monitoring, the Internet of Things, and human–computer interaction. In this paper, we propose a novel and wearable optical microfiber intelligent sensor based on a wavy-shaped polymer optical microfiber (WPOMF) for cardiorespiratory and behavioral monitoring of humans. The optical fibers based on polymer materials are prepared into optical microfibers, fully using the advantages of the polymer material and optical microfibers. The prepared polymer optical microfiber is designed into a flexible wave-shaped structure, which enables the WPOMF sensor to have higher tensile properties and detection sensitivity. Cardiorespiratory and behavioral detection experiments based on the WPOMF sensor are successfully performed, which demonstrates the high sensitivity and stability potential of the WPOMF sensor when performing wearable tasks. Further, the success of the AI-assisted medical keyword pronunciation recognition experiment fully demonstrates the feasibility of integrating AI technology with the WPOMF sensor, which can effectively improve the intelligence of the sensor as a wearable device. As an optical microfiber intelligent sensor, the WPOMF sensor offers broad application prospects in disease monitoring, rehabilitation medicine, the Internet of Things, and other fields