Investigation of strain measurement on paper-based strain sensor using carbon electrical conductive paint

Electrical strain gauge has been used widely in many applications, such as experimental strength of materials and structural health monitoring because of their low cost and durability in making measurements. Recently, a few new sensors have been developed using the constantan alloy to enhance the sensor's response and sensitivity. However, researchers have noticed that electrical conductive paints alternate their electrical resistance when subjected to mechanical strain. This conductivity is given by the conductive network created by the conductive particles in the paint mixture. The conductive network is then altered as a result of the mechanical deformation, changing the material’s electrical properties. This research aims to study the effect of the paper-based strain sensor when the carbon electrical conductive paint is used as a sensor coil in the sensor. We studied the changes in the electrical resistance R as the length of the sensor changed according to the applied strain. The conductive paint was applied on 80gsm A4 printing paper. There are three sensor designs that have been studied. For the first method, the gauge factor for design one is 0.67, the second design gives 0.33 for the gauge factor, and the gauge factor for the third design is 0.50. The design that is suitable for the fabrication of the paper-based strain sensor is design 1 because it has the highest sensitivity compared to other designs. However, the sensor's sensitivity must be enhanced by doing more research to produce a better sensor

Configurable triple wavelength semiconductor optical amplifier fiber laser using multiple broadband mirrors

A configurable, triple wavelength fiber laser based on broadband mirrors (BBMs) and an arrayed waveguide grating (AWG) is demonstrated. The laser uses a semiconductor optical amplifier (SOA) as the primary gain medium due to its inhomogeneous broadening property that allows for the generation high intensity lasing wavelengths. The combination of the AWG and BBMs allows for triple lasing wavelength outputs with channel spacing from 0.8 to 4.0 nm to be obtained. The generated output is adjustable between 1540.6 and 1548.6 nm. The proposed SOA-based system is stable and can be used as a reserve laser source for wavelength division multiplexing systems. © 2019 Wiley Periodicals, Inc

Stable multiwavelength semiconductor optical amplifier-based fiber laser using a 2-mode interferometer

A multiwavelength semiconductor optical amplifier (SOA) fiber laser based on all-fiber two-mode interferometer (TMI) structure is demonstrated. The TMI generates in a comb-like spectrum with a 1-nm wavelength spacing and extinction ratio of 5.7 dB. By incorporating a TMI in the laser cavity, stable multiwavelength operation is obtained with 30 output channels from 1570.8 to 1600.8 nm with peak powers of at least 10 dB from the highest peak. The output comb spectrum and the overall stability of the multiwavelength are also enhanced with by inducing the four-wave-mixing effect in the cavity. The multiwavelength SOA fiber laser shows high operational stability with peak power fluctuations exceeding 1 dB observed only at the 1st, 23rd, 26th, and 30th peaks, which are at the ends of the multiwavelength spectrum

Distributed feedback multimode brillouin–raman random fiber laser in the S-band

A novel S-band multimode Brillouin–Raman random fiber laser based on distributed feedback of Rayleigh scattered light is demonstrated. It relies on a short length, 7.7 km long angle-cleaved dispersion compensating fiber in a mirror-less open cavity. Two 1425 nm laser diodes at a modest operating power amplify a Brillouin pump (BP) signal, which in turn generates a multi-wavelength laser output through the stimulated Brillouin scattering. Eleven Brillouin Stokes lines, spanning from 1515.15 to 1516.00 nm, were obtained at a Raman pump power of 361.66 mW. Out of these, five odd Brillouin Stokes lines were generated with a flat peak power of about 0 dBm

Temporal and amplitude modulation at C-band region using Bi2Te3-based optical modulator

A temporal and amplitude modulator based on few-layers bismuth telluride (Bi2Te3) flakes is demonstrated for C-band operation. The few-layers thick Bi2Te3 flakes are prepared by mechanically exfoliating a Bi2Te3 crystal. As an optical pulse modulator, the Bi2Te3-based saturable absorber (SA) provides stable Q-switching operation at 1561.1 nm with a maximum repetition rate of 70.92 kHz and minimum pulse width of 2.38 µs. As an optical amplitude modulator, two linear regions at different pump power ranges are obtained in the regression line of the peak intensity. The first linear region covers a pump power range from 0.0 to 80.32 mW and corresponds to a modulation efficiency of 0.05 dB/mW, while the second linear region covers a pump power range of 80.32–98.64 mW with a modulation efficiency of 0.81 dB/mW

A simple linear cavity dual-wavelength fiber laser using AWG as wavelength selective mechanism

In this paper, a simple design of linear cavity dualwavelength fiber laser (DWFL) is proposed. Operating in the Cband region stretching from 1538.3 nm to 1548.6 nm, an arrayed waveguide grating (AWG) is used to generate the dualwavelengths output together with a broadband fiber Bragg grating as a back reflector and an optical circulator with a 10% output coupling ratio which acts as a front mirror. The measured average output power of the DWFL is about –5.66 dBm and with a side mode suppression ratio (SMSR) of 53.1 dB. The spacing between the two output wavelengths can be varied from 0.8 nm to 10.3 nm with a stable output and minimum power fluctuations

Synchronous tunable wavelength spacing dual-wavelength SOA fiber ring laser using Fiber Bragg grating pair in a hybrid tuning package

A Dual-Wavelength Semiconductor Optical Amplifier (DW-SOA) based fiber ring laser with synchronous wavelength tunability is proposed and experimentally demonstrated. The SOA gain medium strongly suppresses mode competition, thus allowing stable dual-wavelength laser oscillation. The wavelength spacing of the two lasers can be tuned synchronously using a modified hybrid-tuning package incorporating a pair of Fiber Bragg Gratings (FBGs). The DW-SOA demonstrates a laser output with a wavelength spacing of between 0.10 and 8.30 nm (wavelength shift inequality of 0.08 to 0.75 nm). The relationship between the applied strain and wavelength shift of the two tuning modes is also analyze

Highly stable graphene-assisted tunable dual-wavelength erbium-doped fiber laser

A highly stable tunable dual-wavelength fiber laser (TDWFL) using graphene as a means to generate a highly stable output is proposed and generated. The TDWFL comprises a 1 m long, highly doped erbiumdoped fiber (EDF) acting as the linear gain medium, with a 24-channel arrayed waveguide grating acting as a wavelength slicer as well as a tuning mechanism to generate different wavelength pairs. The tuned wavelength pairs can range from 0.8 to 18.2 nm. A few layers of graphene are incorporated into the laser cavity to induce the four-wave-mixing effect, which stabilizes the dual-wavelength output by suppressing the mode competition that arises as a result of homogenous broadening in the EDF. © 2013 Optical Society of Americ

Multiwall carbon nanotube polyvinyl alcohol-based saturable absorber in passively Q-switched fiber laser

In this work, we demonstrated a compact Q-switched erbium-doped fiber laser capable of generating high-energy pulses using a newly developed multiwall carbon nanotube (CNT) polyvinyl alcohol (PVA) thin film based saturable absorber. Q-switched pulse operation is obtained by sandwiching the thin film between two fiber ferrules forming a saturable absorber. A saturable absorber with 1.25 wt. % of PVA concentration shows a consistency in generating pulsed laser with a good range of tunable repetition rate, shortest pulse width, and produces a high pulse energy and peak power. The pulse train generated has a maximum repetition rate of 29.9 kHz with a corresponding pulse width of 3.49 μs as a function of maximum pump power of 32.15 mW. The maximum average output power of the Q-switched fiber laser system is 1.49 mW, which translates to a pulse energy of 49.8 nJ. The proposed method of multiwall CNT/PVA thin film fabrication is low in cost and involves uncomplicated processes

Single mode EDF fiber laser using an ultra-narrow bandwidth tunable optical filter

Single longitudinal mode (SLM) erbium-doped fiber (EDF) laser operation using a commercialized ultra-narrow bandwidth optical filter has been demonstrated. A 2-m long EDF with an absorption coefficient of 24 dB m-1 at the pump wavelength is used as gain medium. The ultra-narrow tunable filter is used for selection of a single longitudinal mode from the available spectrum of multiple modes, which originally exist in the FBG's reflection spectrum. Our approach provides a relatively simple and direct method for realization of SLM operation. A high-resolution optical spectral analyser with a resolution of 0.16 pm isused to observe the output spectrum. To verify the SLM operation, the delayed self-heterodyne methodis used, giving a measured laser linewidth of 61.5 kHz