The Characteristics and Application of Polymer Optical Fiber

The recent development of polymer optical fiber (POF) at home and abroad was summarized.The special characteristics of the perfluorinated POF were introduced and its wide potential application was predicted.POF is the most suitable in conjunction network project,especially using with quartz optical fibers.Facing this market opportunity,it is a right choice to unit colleges,research institutions and manufacture corporations to accelerate the industrialization of POF.

Properties of Single Mode Polymer Optical Fiber

The density,dynamic modulus,Youngs modulus,tensile strength,extension properties,Fourier transform infrared spectrum and differential scanning calorimetry have been measured and discussed for single mode polymethyl-methacrylate optical fiber.The results show that the fiber can provide large strain range for polymeric optical fiber Bragg gratings.

Knot-inspired optical sensors for slip detection and friction measurement in dexterous robotic manipulation

Friction plays a critical role in dexterous robotic manipulation.However,realizing friction sensing remains a challenge due to the difficulty in designing sensing structures to decouple multi-axial forces.Inspired by the topological mechanics of knots,we construct optical fiber knot(OFN)sensors for slip detection and friction measurement.By introducing localized self-contacts along the fiber,the knot structure enables anisotropic responses to normal and frictional forces.By employing OFNs and a change point detection algorithm,we demonstrate adaptive robotic grasping of slipping cups.We further develop a robotic finger that can measure tri-axial forces via a centrosymmetric architecture composed of five OFNs.Such a tactile finger allows a robotic hand to manipulate human tools dexterously.This work could provide a straightforward and cost-effective strategy for promoting adaptive grasping,dexterous manipulation,and human-robot interaction with tactile sensing.

Surface Plasmon Resonance Sensors Based on Polymer Optical Fiber

Surface Plasmon Resonance （SPR） is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering （SERS） probe. Long-period fiber gratings are fabricated on single mode polymer optical fiber （POF） with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.

Picosecond gain-switched polymer fiber random lasers

Random lasers are a type of lasers that lack typical resonator structures,offering benefits such as easy integration,low cost,and low spatial coherence.These features make them popular for speckle-free imaging and random number generation.However,due to their high threshold and phase instability,the production of picosecond random lasers has still been a challenge.In this work,we have developed three dyes incorporating polymer optical fibers doped with various scattering nanoparticles to produce short-pulsed random fiber lasers.Notably,stable picosecond random laser emission lasting600 ps is observed at a low pump energy of 50μJ,indicating the gain-switching mechanism.Population inversion and gain undergo an abrupt surge as the intensity of the continuously pumped light nears the threshold level.When the intensity of the continuously pumped light reaches a specific value,the number of inversion populations in the“scattering cavity”surpasses the threshold rapidly.Simulation results based on a model that considers power-dependent gain saturation confirmed the above phenomenon.This research helps expand the understanding of the dynamics behind random medium-stimulated emission in random lasers and opens up possibilities for mode locking in these systems.

Liquid Level Sensor Based on CMFTIR Effect in Polymer Optical Fiber

The macro-bending induced optical fiber cladding modes frustrated total internal reflection effect is used to realize the liquid level probe with a simple structure of single macro-bend polymer optical fiber loop. The test results show that the extinction ratio reaches 1.06dB. ＂First bath＂ phenomenon is not obvious （about 0.8%）. The robustness of the sensor is better, and the ability of anti-pollution is stronger compared with the conventional sensors. The process of making this sensing probe is extremely easy, and the cost is very low.

Development of Flexible Luminous Fabrics for Photodynamic Therapy in Biomedical Applications

Fabrics integrating with side-emitting polymer optical fiber( SE-POF) have great potentials for photodynamic therapy( PDT),which is a form of phototherapy recognized as a treatment strategy that is both minimally invasive and minimally toxic.Preliminary research has been undertaken to develop flexible luminous fabrics( FLF) device for PDT used in biomedical applications. The FLF device consists of SE-POFs, textile substrates,light source( LEDs or laser) with proper wavelength,and optical fiber coupling,etc. Different patterns of the fabrics were designed and fabricated purposely,and the light illumination effect was tested including the light power emitting from the patterned optical fiber fabrics,the stability of the illumination,and the light with different wavelengths. The work contributes to the successful development of an efficient and pain-alleviated illumination device for PDT in biomedical application.