Temporal soliton: generation and applications in optical communications

In general, the temporal and spectral shape of a short optical soliton pulse does not change during propagation in a nonlinear medium due to the Kerr effect which balances the chromatic dispersion. Microring resonators (MRRs) can be used to generate chaotic signals. The smaller MRR is used to form the stopping and filtering system. The employed optical material was InGaAsP/InP, which is suitable for use in the practical devices and systems. The tuning and manipulation of the bandwidth of the soliton signals is recommended to control the output signals. The MRRs can be applied to produce ultra-short pulses, where the medium has a nonlinear condition, thus, using of soliton laser becomes an interesting subject. Therefore, an ultra-short pulse in the scope of pico and femtoseconds soliton pulses can be utilized for many applications in engineering communications. In order to obtain smaller bandwidth of the optical soliton pulses, we propose integrating series of MRRs. In this study, 5 fs soliton pulse could be generated using a series of five MRRs. The soliton signals experience less loss during the propagation, where they are more stable compared to normal conventional laser pulses. Using the series of MRRs connected to an add/drop system, shorter soliton bandwidth and highly multi soliton pulses can be obtained. Therefore, generation of ultra-short multi picosecond (1.2 and 1.3 ps), could be performed, where the radius of the add/drop system has been selected to 50 and 300 μm respectively

Characterization of erbium doped photonic crystal fiber

Photonic crystal fibers (PCFs) are a new emerging research area, and have been undergoing rapid development in recent years due to their unique and excellent optical properties and features. Studies on the characteristics of various types of PCFs have been reported. However, characterization on erbium-doped PCF has not previously been investigated. Therefore, in this paper, we have modeled an erbium-doped core PCF which has 7 rings of hexagonal air holes. The PCF structure, with a perfectly matched layer (PML), is modeled and simulated using Finite Element Method (FEM) via COMSOL software. The PML is optimized by varying the radius and thickness of the layer. Modal properties of the PCF have been investigated in terms of its effective index of the supported fundamental mode, confinement loss and thickness of the perfectly matched layer. This erbium-doped PCF has a confinement loss of 1.0E-6 at 1500 nm and a maximum effective refractive index of 1.476. This paper gathers useful data, which could be used for studying the characteristics of a PCF

Switching power improvement of hybrid polymer-silica based MMI thermo-optical switch

A new hybrid polymer-silica multimode interference (MMI) switch with single heater electrode is demonstrated. A heater electrode is used to change the refractive index within the different section of the MMI to realize switching operation due to the thermo-optic (TO) effect in polymer-silica optical waveguide. Switching power analysis has been done by employing straight heater electrode followed by implementation of trapezoidal structure. The simulation result shows that the trapezoidal structure of heater electrode helps to achieve significant improvements of MMI switch performance particularly in switching power reduction by 33.37% as compared to the rectangular structure

Post-Irradiation Mechanical Properties Prediction of Al 6070 of MTR-Fuel Bundle for Cutting Process

The Al 6070 is the side plate material of the MTR-fuel plate bundle. These post-irradiation mechanical properties will be used in the side plate cutting process to obtain certain plates from the MTR-fuel plate bundle. This activity is part of a series of post-irradiation test processes from the MTR-fuel plate bundle in order to determine its performance. After testing in the form of a bundle (assembly), then continued testing of certain plates from the bundle. Disassembly of the plate is carried out by cutting along the two side plates (aluminum alloy) that clamp the plate. The mechanical properties of the workpiece material are important factors that affect the conditions of the machining (cutting) process. Prediction of post-irradiation mechanical properties was carried out using the change percentage of before and after irradiation of other aluminum alloys. The prediction carried out with the Si transmutation as the dominant one affects the post-irradiation mechanical properties changes in aluminum alloys. The change percentage added the mechanical properties of the pre-irradiated side plate material of the MTR-fuel plate bundle. Pre-irradiation testing of the Al 6070, namely chemical composition tests, pre-irradiation mechanical properties tests, including hardness tests (micro), and tensile tests (max stress, yield stress, and % elongation). Prediction of changes in mechanical properties of side plate material (aluminum alloy, Al 6070) before irradiation, compared to after irradiation is: hardness value from 98.51 to 127 (gf/µm2), tensile strength from 265.371 to 398 (N/mm2), the yield strength from 204.2 to 306 N/mm2

Intensity-modulated temperature sensor based on fiber interferometer with optical bandpass filtering

An intensity-modulated temperature sensor based on fiber Mach-Zehnder interferometer (MZI) is proposed and demonstrated. The sensor is constructed using single mode fiber (SMF) and multimode fiber (MMF) in SMF-MMF-SMF-MMF-SMF sequence. The sensing system is power-interrogated, relies on an optical bandpass filtering of the sensor output at a predetermined wavelength which converts any change in sensor spectra into power change. This sensing scheme is very cost effective, as the temperature can be directly quantified from photodetector voltage measured at the filter output. Furthermore, sensor fabrication only involves conventional fusion splicing process between standard SMF and MMF. Experimental result shows that a sensor with length 20 mm produces linear response of -0.48 mV/°C at 1532 nm passband wavelength, good long-term stability with negligible voltage drift and fluctuation, and wide measurement range within 30-180°C. The proposed scheme potentially can be applied in fiber interferometer sensors for measurement of other physical parameters such as strain, refractive index and vibration