Angularly Cascaded Long-Period Fiber Grating for Curvature and Temperature Detection.

A high-sensitivity curvature sensor with dual-parameter measurement ability based on angularly cascaded long-period fiber grating (AC-LPFG) is proposed and experimentally demonstrated, which consists of two titled LPFGs (TLPFGs) with different tilt angles and the same grating period. AC-LPFG was fabricated by using a deep ultraviolet laser and an amplitude-mask in our laboratory. The experimental results show that simultaneous measurement of curvature and temperature can be achieved by monitoring the wavelengths of two resonant peaks for different TLPFGs.

Shortwave infrared single-pixel spectral imaging based on a GSST phase-change metasurface.

Shortwave infrared (SWIR) spectral imaging obtains spectral fingerprints corresponding to overtones of molecular vibrations invisible to conventional silicon-based imagers. However, SWIR imaging is challenged by the excessive cost of detectors. Single-pixel imaging based on compressive sensing can alleviate the problem but meanwhile presents new difficulties in spectral modulations, which are prerequisite in compressive sampling.

Low bending loss few-mode hollow-core anti-resonant fiber with glass-sheet conjoined nested tubes.

A novel hollow-core anti-resonant fiber (HC-ARF) with glass-sheet conjoined nested tubes that supports five core modes of LP01-LP31 with low mode couplings, large differential group delays (DGDs), and low bending losses (BLs) is proposed. A novel cladding structure with glass-sheet conjoined nested tubes (CNT) is induced for the proposed HC-ARF which can suppress mode couplings between the LP01-LP31 modes and the cladding modes. The higher-order modes (HOMs) which are LP11-LP31 modes also have very low loss by optimizing the radius of the nested tube and the core radius.

GuLiM: A Hybrid Motion Mapping Technique for Teleoperation of Medical Assistive Robot in Combating the COVID-19 Pandemic.

Driven by the demand to largely mitigate nosocomial infection problems in combating the coronavirus disease 2019 (COVID-19) pandemic, the trend of developing technologies for teleoperation of medical assistive robots is emerging. However, traditional teleoperation of robots requires professional training and sophisticated manipulation, imposing a burden on healthcare workers, taking a long time to deploy, and conflicting the urgent demand for a timely and effective response to the pandemic. This paper presents a novel motion synchronization method enabled by the hybrid mapping technique of hand gesture and upper-limb motion (GuLiM).

User-Interactive Robot Skin With Large-Area Scalability for Safer and Natural Human-Robot Collaboration in Future Telehealthcare.

With the fourth revolution of healthcare, i.e., Healthcare 4.

Multiwavelength laser designed for single-frame digital holography.

In this paper, we present a tailored multiwavelength Yb-fiber laser source in the 1.03 μm spectral region for spatially multiplexed digital holographic acquisitions. The wavelengths with bandwidths below 0.

Dynamics of long-period gratings tuned with internal fiber electrodes.

The physics of electrically switched long-period grating in a twin-hole fiber with internal electrodes is studied. Dynamic measurements for the two polarizations show how the grating spectra shift in time due to the mechanical stress and heat transfer in the core and the cladding.

Actively Q-switched all-fiber laser with an electrically controlled microstructured fiber.

Actively Q-switching of an all-fiber laser system is demonstrated. The active element is a polarization switch with nanosecond risetime based on a microstructured fiber with electrically driven internal electrodes. Optical feedback between two 100% reflectors is inhibited until a nanosecond current pulse Q-switches the laser.

All-fiber single-pulse selection and nanosecond gating.

Two functions normally attributed to Pockels cells are performed with internal-electrode microstructured fiber components. Single-pulse selection out of a 100 MHz mode-locked pulse train is demonstrated using all-fiber nanosecond polarization rotation. Additionally, off-on-off gating with duration approximately 13 ns is achieved with a polarization rotator made out of a four-hole silicate fiber.

Birefringence switching of Bragg gratings in fibers with internal electrodes.

A fiber Bragg grating was written in a side-hole fiber with internal metal alloy electrodes. The initial geometrical birefringence of this fiber gives rise to two Bragg resonances separated by 43 pm. Nanosecond risetime current pulses of up to 23 A were applied to the metal electrode, which heated and expanded rapidly.

Nanosecond switching of fiber Bragg gratings.

A FBG was written in a two-hole fiber with internal alloy electrodes. Nanosecond high current pulses cause metal expansion, increase birefringence and tune the gratings with a response time of 29 ns. This short length, low loss, all-spliced high-speed wavelength switching devices described here has potential use in Q-switching fiber laser.