Multiwavelength fiber laser in four mode fiber

Multiwavelength fiber laser is a nonlinear phenomenon that has a great potential for optical communication system. A stable triple-wavelength fiber laser in four mode fiber had been demonstrated experimentally by employing Sagnac filter in a simple close loop laser cavity. The Sagnac loop filter configuration was constructed using a 2 m of polarization maintaining fiber (PMF), a 3 dB coupler and a polarization controller. The laser is able to sustain triple-wavelength laser generation at 13.1 dBm output power of Erbium-Doped Fiber Amplifier (EDFA) as all laser wavelengths produced less than 0.25 nm fluctuation for over 20 min of unstoppable lasing operation. This laser configuration also has flexibility to perform single, dual and triple wavelength laser by controlling the EDFA output power

The comparison of dual wavelength fiber laser spectrum in SMF and HNLF by utilizing laser diode

A dual-wavelength erbium-doped fiber (EDF) fiber ring laser in single mode fiber and highly nonlinear fiber is demonstrated and both optical spectrums are compared at 400 mA of Laser Diode (LD) output. The fiber ring laser cavity incorporated sagnac loop had been applied for the laser to lase two wavelengths simultaneously due to high birefringent in polarizaton-maintaining fiber (PMF). Experimental results show that, owing to the contributions of two degenerate fourwave mixings (FWM) in the HNLF and the dual-wavelength proposed fiber laser is quite stable with small fluctuation power in 1.93 dB within 24 minutes in HNLF

Passively mode-locked laser using an entirely centred erbium-doped fiber

This paper describes the setup and experimental results for an entirely centred erbium-doped fiber laser with passively mode-locked output. The gain medium of the ring laser cavity configuration comprises a 3 m length of two-core optical fiber, wherein an undoped outer core region of 9.38 μm diameter surrounds a 4.00 μm diameter central core region doped with erbium ions at 400 ppm concentration. The generated stable soliton mode-locking output has a central wavelength of 1533 nm and pulses that yield an average output power of 0.33 mW with a pulse energy of 31.8 pJ. The pulse duration is 0.7 ps and the measured output repetition rate of 10.37 MHz corresponds to a 96.4 ns pulse spacing in the pulse train

Degeneration of four wave mixing in 500 m step index two mode fiber

Four wave mixing (FWM) in two-mode fiber was experimentally demonstrated at 24.7 dBm of output Erbium doped fiber amplifier (EDFA). The 0.5 km two mode fiber in laser cavity enhances the performance of four wave mixing by suppressing the homogenous broadening effect in erbium-doped fiber and perform a stable oscillation. At output EDFA approaches to 24.7 dBm, FWM is generated and the increasing of output EDFA induced the optical signal to noise ratio (OSNR) of all laser peaks

Peningkatan Hasil Belajar Matematika dengan Menggunakan Metode Demonstrasi Kelas IV Sekolah Dasar

This study aims to improve the learning outcomes of students in the fourth grade elementary school 10 Riam length . The method used in this research is classroom action research method consists of three ( 3 ) cycles . Subjects were fourth grade students of SD Negeri 01 Riam length consisting of 21 students . Planning learning of mathematics with demonstration method in the fourth grade students of SDN 10 Riam length of cycle 1 the average score obtained 2,6.Pada obtained 2,7.Pada cycle 2 cycle 3 was obtained 3.0 . Implementation of learning mathematics has increased from cycle 1 to cycle 3 , wherein the first cycle of the implementation of learning an average score of 2.8 was obtained obtained 2,9.Pada .At 2 cycles 3 cycles obtained 's gained 3.0 . Mathematics learning outcomes demonstration method in the fourth grade students of SDN 10 Riam length with an average value of 65.23 in the first cycle and the second cycle of 80,47.Pada third cycle of 94.76

Short term durability of steel-strap confined concrete

Steel strapping tensioning technique (SSTT) confinement has been proven as a type of external confinement to retrofit and upgrade concrete structures. Their remarkable enhancement to concrete mechanical properties, practicing active lateral confinement, low cost, easy to operate, time saving and no structure interruption during application have brought this technique as of the most affordable technique for column confinement, especially for high strength concrete (HSC) which naturally behaves insufficient in ductility. Although a great number of previous studies have demonstrated the performance of SSTT confinement, there are several anxieties related to the long term behaviour of SSTT confined columns which have yet been implemented especially in real hostile condition. Environmental effects, such as ultraviolet radiation exposure and saline solution (sea water) may affect the confining material properties, and therefore decrease the performance of the confined columns. In this study a total of twenty HSC specimens with dimension of 100 mm and 200 mm in diameter and height respectively were prepared, volumetric-identically pre-tensioned with steel strap and exposed to three conditions: indoor, outdoor and saline water for three months. The exposed specimens were monotonically tested and their performance was studied through the stress-strain relationship, mode of failure and degree of corrosion. The results show that none of the forenamed environmental conditions have exaggerating influence on the performance of the SSTT confined concrete specimens even some material has been severely corroded. It is then parallel compared with existing FRP confinement studies and the result proves that SSTT confinement able to possess the highest strength performance under similar environmental exposure

Prediksi Kedatangan Turis Asing Ke Indonesia Menggunakan Backpropagation Neural Networks

In this paper, a backpropagation neural network (BPNN) method with time series data have been explored. The BPNN method to predict the foreign tourist's arrival to Indonesia datasets have been implemented. The foreign tourist's arrival datasets were taken from the center agency on statistics (BPS) Indonesia. The experimental results showed that the BPNN method with two hidden layers were able to forecast foreign tourist's arrival to Indonesia. Where, the mean square error (MSE) as forecasting accuracy has been indicated. In this study, the BPNN method is able and recommended to be alternative methods for predicting time series datasets. Also, the BPNN method showed that effective and easy to use. In other words, BPNN method is capable to producing good value of forecasting.Keywords - BPNN; foreign tourists; BPS; MSEPemanfaatan backpropagation neural network (BPNN) dengan data deret waktu telah digunakan dalam paper ini. Metode BPNN telah digunakan untuk memprediksi data kedatangan turis asing ke Indonesia, dimana data turis tersebut diambil dari badan pusat statistik Indonesia (BPS). Hasil pengujian menunjukkan bahwa metode BPNN dengan dua lapisan tersembunyi mampu memodelkan dan meramalkan data kedatangan turis asing ke Indonesia yang diindikasikan dengan nilai mean square error (MSE). Penelitian ini merekomendasikan bahwa metode BPNN mampu menjadi alternative metode dalam memprediksi data yang berjenis deret waktu karena metode BPNN efektif dan lebih mudah digunakan serta mampu menghasilkan akurasi nilai peramalan yang baik

A sensitive acoustic sensor using fiber bragg grating based on strain compensation

An acoustic sensitivity single ring fiber sensor with enhanced pressure sensitivity is designed by using Fiber Bragg Grating (FBG). Measurement sensitivity of the this fiber sensor is 0.3714 με/Hz. This sensor exhibited a good acoustic sensitivity, showing that the sensor has good sensing properties for the detection of the acoustic signals