Polymethyl Methacrylate Plastic Optical Fiber Research Articles

Cellular Guardband NB-IoT Performance Over PMMA Plastic Optical Fibers

Cellular Guardband NB-IoT Performance Over PMMA Plastic Optical Fibers

Study on thermal protection and temperature of PMMA plastic optical fiber for concentrated sunlight transmission in daylighting

Daylighting system by concentrating and transmitting sunlight through optical fiber is an emerging technology of direct utilization of solar energy. In this work, a sunlight concentrating and transmitting system via plastic optical fibers was developed and investigated. This study addressed the overheating problem of plastic optical fibers under highly concentrated light irradiation. Polymethylmethacrylate (PMMA) plastic fibers have a strong absorption in the infrared band. The PMMA plastic fiber generates serious heat under highly concentrated light transmission, which leads to its overheating and burning. In this study, an incident light filtering method based on the combination of infrared filter and insulating glass is proposed. By filtering out the infrared band light with significant thermal effect, the PMMA plastic optical fibers are guaranteed to be within a safe working temperature range. Experiments demonstrated that the developed filter system can ensure the safe operation of PMMA plastic optical fibers at the concentration level of about 4300 suns. This shows that it is feasible to use low-cost plastic optical fiber for highly concentrated daylighting system.

Application of highly concentrated sunlight transmission and daylighting indoor via plastic optical fibers with comprehensive cooling approaches

Sunlight Concentrated and transmission for daylighting via optical fibers is a booming technology of direct utilization of solar energy. It uses optical fibers to introduce sunlight deep into building interior. In this work, a sunlight concentrating and transmitting system via plastic optical fibers was developed and tested. This study addressed the cooling problem of the plastic optical fibers under highly irradiation. Polymethylmethacrylate (PMMA) plastic fibers have a strong absorption effect on infrared light, which means that plastic fibers heat up so much when they transmit focused sunlight that they burn. In this study, a comprehensive cooling approach was developed to solve the overheating problem of plastic optical fibers, which consists of an infrared filter, cooling water and a homogenizer. The transmission efficiency of the system was measured to be about 15%. Experiments show that the comprehensive cooling measures developed can ensure that PMMA plastic optical fibers are in a safe temperature range. This shows that it is feasible to use low-cost plastic optical fibers instead of expensive silica fiber to transmit high flux for daylighting.

Dissolved oxygen sensing characteristics of plastic optical fiber coated with hydrogel film

This paper proposes a dissolved oxygen sensing system based on PMMA plastic optical fiber covered at one end with biocompatible PEGDA (Polyethylene glycol diacrylate) hydrogel film. PEGDA, 2-hydroxy-2-methyl-propiophenone and DI water mixture was used as hydrogel precursors, and a certain concentration of oxygen-sensitive fluorescent indicator was incorporated into it. Fluorescence quenching method was used to detect dissolved oxygen in water, the doping concentration of fluorescent indicator in the hydrogel film was optimized. The experimental results indicate that the plastic optical fiber coated with hydrogel sensing film has good reproducibility, and the response time is within 10 s. The sensing characteristics of dissolved oxygen at 30 °C, 35 °C, and 40 °C were tested respectively, and the results showed that the linearity of the system is best at 35 °C. Within the range of pH 2–12, the fluorescence intensity of the fluorescent indicator is very stable. The sensor with biocompatible material is expected to be applied to the monitor of dissolved oxygen in the domain of biomedicine.

Iodine ions sensing based on fluorescence quenching method and hydrogel fiber doped with fluorescein

This paper presents an iodine ions fluorescence quenching sensor based on hydrogel fiber doped with fluorescein. The hydrogel fiber was made by photo-crosslinking with core-cladding structure made from PEGDA precursor solutions with different concentration. Compared with calcium alginate cladding material, this structure is less susceptible to damage and the thickness of the cladding is controllable, which significantly reduces the loss of the hydrogel fiber. Experimental results show that the loss of the cladding-free hydrogel is 1.669 dB/cm ± 0.4 dB/cm, and the loss of the core-cladding hydrogel fiber is 0.597 dB/cm ± 0.2 dB/cm. By analyzing the properties of different hydrogel precursor solutions before and after photo-crosslinking, a functional hydrogel fiber doped with fluorescein for measuring iodine ions with numerical aperture of 0.3932 and mode number about 17 was fabricated. The hydrogel fiber shows high coupling efficiency with PMMA plastic optical fiber. The sensor of iodine ions exhibited a linear range of 0 ∼36 mM and the detection limit was calculated to be 26nM. The system also shows good stability and repeatability. Hydrogel fibers shows good biocompatibility and flexibility, which will have broad application prospects in biological area in the future.

Multi-Format Wired and Wireless Signals over Large-Core Plastic Fibers for In-home Network

This paper presents successful simultaneous transmission of an IEEE802.11n 16-QAM 40 MHz bandwidth WLAN, 9 64-QAM LTE-A bands, and a 1.7 Gb/s 4-PAM baseband signal over 50 m of 1-mm core diameter graded-index polymethyl methacrylate plastic optical fiber. The optical link is an intensity modulation with direct detection link, using a Fabry Perot laser diode emitting visible light at 650 nm and a p–i–n Silicon photodiode followed by a transimpedance amplifier. The signals were simultaneously transmitted using frequency division multiplexing. The radio signals were sent transparently over the optical link by analog radio over fiber technique. The LTE-A peak power was reduced by digital signal clipping at the transmitter side, which results in error vector magnitude values complying with the standard. Furthermore, the noise figure of the optical link was measured and its impact on the received signal is analyzed. After the optical link, the radio signals were re-emitted over an indoor line-of-sight wireless link up to 12-m distance.

Slab Waveguide and Optical Fibers for Novel Plasmonic Sensor Configurations.

The use of plasmonic sensor devices often requires replaceable parts and disposable chips for easy, fast and on-site detection analysis. In light of these requests, we propose a novel low-cost surface plasmon resonance sensor platform for possible selective detection of analytes in aqueous solutions. It is based on a Polymethyl methacrylate (PMMA) slab waveguide with a thin gold film on the top surface inserted in a special holder, designed to produce the plasmonic resonance at the gold-dielectric interface. A wide-band light is launched in the PMMA slab waveguide through a trench realized in the holder directly, and illuminated with a PMMA plastic optical fiber (POF) to excite surface Plasmon waves. The output light is then collected by another PMMA POF kept at the end of the slab at an angle of 90° to the trench, and carried to a spectrometer. In this configuration, the trench has been used because a large incident angle is required for surface plasmon resonance excitation. The preliminary results showed that the sensor’s performances make it suitable for bio-chemical applications. The easy replacement of the chip allows for the production of an engineered platform by simplifying the measurement procedures.

Multiband LTE-A and 4-PAM Signals Over Large-Core Plastic Fibers for In-Home Networks

This letter presents the transmission of eight standard compliant 64-QAM long term evolution advanced (LTE-A) bands and 1.4 Gb/s 4-pulse amplitude modulation (PAM) signals over 20 m of 1 mm core diameter graded-index polymethyl methacrylate plastic optical fiber. The optical transceiver consists of a red light VCSEL and a p-i-n photodiode followed by a transimpedance amplifier. The LTE-A signals were transparently transmitted with the radio-over-fiber technique and without complex frequency conversion at the receiver side. A gain control technique in the digital domain was used to avoid entering the VCSEL saturation regime. Digital filtering was employed at the transmitter and receiver sides to improve the spectrum shaping of the 4-PAM and LTE-A signals. The proposed system offers a single infrastructure in-home solution capable of accommodating wired services as well as multiband LTE-A wireless services. Only low-cost components were considered in this letter in order to provide a reliable and inexpensive solution for high-capacity in-home networks.

Radiation Dosimeter Using an Extrinsic Fiber Optic Sensor

A novel extrinsic optical fiber X-ray dosimeter for biomedical applications is presented in this paper. The primary focus of the sensor is to measure low doses of ionizing X-ray radiation. The material in the sensor tip scintillates upon exposure to radiation and the resultant low level scintillating light is coupled to a polymethylmethacrylate plastic optical fiber, which guides it toward a distant fluorescent optical spectrometer. The optical spectrometer measures the low level scintillating light from the sensor and converts the ionizing radiation energy to measurable arbitrary optical intensity units. Initial testing showed the scintillating optical fiber X-ray dosimeter exhibits an acceptable sensitivity upon excitation from a calibrated X-ray source. Further examinations of the sensor revealed good response and repeatability of measurement for various levels of low energy ionizing X-ray energy. The sensor was found to exhibit a maximum of 3.23% variance from the average value over ten repetitions. The sensor is sensitive from 50 kVp X-ray energy which continued exponentially up to 140 kVp where the response began to taper off. The sensor demonstrated excellent spectral response upon exposure to 6 MV and 15 MV ionizing X-ray radiation energy from a Siemens Avant Garde linear accelerator. It showed excellent repeatability of measurement upon repeated actuation of the radiation over short bursts of time. The sensor demonstrates very good stability of response during on radiation periods, showing a maximum of 2% variation of the full scale value in each case. This type of optical fiber X-ray dosimeter was tested in the University of Limerick (Ireland), the National Institute for Lasers, Plasma and Radiation Physics (Romania), and the Galway Clinic in Ireland. Further investigations were performed by all three facilities to better characterize additional features of the sensor for different X-ray radiation energies.

Dielectric Fresnel zone plates on optical fibers for micro-focusing applications

In this paper, we present a novel fabrication technique for constructing light focusing lenses, dielectric Fresnel zone plates on both flat wafers and tips of plastic optical fibers (POFs). SU-8 zone plate structures are made on glass substrate by photolithography with ink-printed soft mask, and then used as the template for hot embossing on the tip of PMMA POF. Focusing behavior for both 472 and 633nm laser beams and LEDs in different colors are observed on glass wafers and POF tips, indicating that the proposed dielectric Fresnel zone plates can be built onto both substrate by a direct hot embossing process which may lead to a high volume production at low cost. Light intensity measurement on POFs proves that light focusing is achieved while intensity is maintained. This structure is expected to have broad applications in micro-imaging, micro-focusing as well as point-of-care medical surgeries.

Effects of neutrons and gamma-rays on polymethylmethacrylate plastic optical fiber

The effects of neutron and gamma-ray irradiation on a polymethylmethacrylate (PMMA) plastic optical fiber (POF) were investigated. An improvement in the optical transmission was observed at the beginning of irradiation, but radiation damage (radiation-induced transmission loss in the visible wavelength range) increased as the irradiation continued. To determine the effects of neutrons and gamma-rays, the amount of energy absorbed in the PMMA POF was calculated using the PHITS codes. Energy deposition in the fiber was calculated considering nuclear reactions listed in the nuclear data file used for the Monte Carlo N-particle transport code. The effects of neutron and gamma radiation were observed to be similar with absorbed energy less than 1.2kGy. However, the transmission loss induced by neutrons was larger than that induced by gamma-rays when higher energy was deposited.

Stimulated emission and ultrafast optical switching in a ter(9,9′-spirobifluorene)-co -methylmethacrylate copolymer

A methacrylate-functionalized 9,9′-spirobifluorene trimer is copolymerized with methylmethacrylate (MMA). The photophysical characterization of this copolymer using pump-probe studies, in solution, as films and in plastic optical fibers (POFs) demonstrates that it shows interesting photonic properties for data communication such as high-stimulated emission cross section (σSE = 2.5 × 10−16 cm2), good thermal, and optical stability, the ability to perform all-optical ultrafast switching, and low attenuation when doped into POFs. In addition, the material shows interesting optically induced conformational control in solution and the studies demonstrate the surprising result that intrachain polaron pairs can be generated even in well-isolated 3-unit oligomers. Although the material is not yet soluble enough in MMA to create highly efficient photonic devices and the gain spectrum is not optimized to overlap with the region of low attenuation in polymethylmethacrylate POFs, these studies are a good starting point to further optimize copolymers for incorporation into POF networks. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010

All fiber N × N fused tapered plastic optical fiber (POF) power splitters for photodynamic therapy applications

We fabricated various types of plastic optical fiber (POF) fused taper N × N splitters ( N = 4, 6, 8, 10, 20, 30, and 60). Inert gas was electrically heated and injected through a nozzle to provide an oxygen-free hot zone to process PMMA POF fused taper. The devices showed unique splitting characteristic to provide a dominant direct output port along with N − 1 weakly coupled output ports, which might have a significant potential in photodynamic therapy applications.

Reversible UV degradation of PMMA plastic optical fibers

Laser-induced fluorescence, Raman and absorption spectroscopy are used to investigate reversible degradation of transmission in PMMA optical fibers. When exposed to 254nm UV light, optical transmission of PMMA plastic optical fiber in 400–800nm range shows a significant increase in attenuation for shorter wavelengths. Over a period of 10 days following UV exposure, the transmittance of the plastic fiber recovers to a significant fraction of its pre-exposure value. UV-exposed fiber exhibits strong laser-induced fluorescence with 488nm argon-ion laser. This fluorescence spans a spectral region between 450nm and 750nm with a peak around 580nm. The fluorescence intensity decreases over several days following UV exposure. Likewise, Raman is also used to investigate degradation process. Freshly UV-exposed fiber shows total absence of Raman spectrum of PMMA. Following UV exposure, recovery of Raman signal over several days is correlated to the recovery of fiber transmittance as well as the decay of laser-induced fluorescence. A widely believed plausible explanation for UV-induced increase of attenuation involves formation of different macro radicals which recombine progressively after UV is stopped. Laser-induced fluorescence over several days is reported here providing direct evidence for molecular-level deterioration and recovery of PMMA.

Modeling, design, growth and characterization of red wavelength range microcavity emitters for plastic optic fiber applications

Resonant cavity light emitting diodes (RC-LEDs) and vertical cavity surface emitting lasers (VCSELs) for the red wavelength range are presented in the paper. A wide variety of simulation tools were employed in the device design and optimization and the good agreement between simulations and measurements enabled effective device development. Our red wavelength range RC-LEDs were mainly intended for short-haul communication systems based on polymethyl methacrylate plastic optical fiber and were optimized accordingly. They are achieving, under different structure and working regime variants, high output power (15 mW), high external efficiency (9.5%), record small-signal modulation bandwidth (f-3dB up to 350 MHz), error-free back-to-back transmission rates beyond 622 Mbits/s, adjustable far-field pattern and good POF coupling efficiency with reasonably wide tolerances and without using auxiliary optics. In view of the possible use of graded-index POFs, free-space transmission and other high bandwidth or high spectral purity applications, VCSELs in the red wavelength range were also realized. They have achieved sub-milliamp room-temperature (RT) continuous-wave (CW) lasing for an 8 μm diameter emission window and exhibited an external quantum efficiency of 6.65% for 10 μm devices in RT CW operation. The VCSEL structures were far from optimal – not even incorporating all the RC-LED structure refinements – and significant improvement in performance characteristics are predicted for the optimized layer structure.

Red Wavelength Range Microcavity Emitters

State-of-the-art resonant cavity light emitting diodes (RC-LEDs) and vertical cavity surface emitting lasers (VCSELs) for the red wavelength range are presented in the paper. Our red wavelength range RC-LEDs were mainly intended for short-haul communication systems on polymethyl methacrylate plastic optical fiber and were optimized accordingly. They achieve, under different structure and working regime variants, high output power (15 mW), high external efficiency (9.5%), record small-signal modulation bandwidth (f -3dB up to 350 MHz), error free back-to-back transmission rates beyond 622 Mbit/s, adjustable far-field pattern and good POF coupling efficiency with reasonably wide tolerances and without using auxiliary optics. In view of the possible use of graded-index POFs, free-space transmission and other high bandwidth or high spectral purity applications, VCSELs in the red wavelength range were also realized. They have achieved sub-milliamp room-temperature (RT) continuous-wave (CW) lasing for an 8 μm diameter emission window and exhibited an external quantum efficiency of 6.65% for 10 μm devices in RT CW operation. The VCSELs, being only assessment devices, were not optimized, and significant improvement in performance characteristics is predicted for the optimized structures.

Les fibres optiques plastiques perfluorées et à gradient d'indice

The PMMA plastic optical fibers with step index are cheap and easy to use. So they would be interesting for local area networks if their attenuations and their bandwidths could be improved. - The development of new perfluorinated polymers having a very weak absorption allowed the fabrication of fibers very clear in the same spectral range as the silica fibers. - The settling of process for controlling the index profile during the realization of preforms provided fibers having bandwidths sufficient for the bit rate of the dealt networks.