Sulaiman Wadi Harun

Bio: Sulaiman Wadi Harun is an academic researcher from University of Malaya. The author has contributed to research in topics: Fiber laser & Saturable absorption. The author has an hindex of 44, co-authored 1107 publications receiving 10844 citations. Previous affiliations of Sulaiman Wadi Harun include Airlangga University & Peninsular Malaysia.

Current sensor based on microfiber knot resonator

Abstract: A compact current sensor using a microfiber knot resonator (MKR) is demonstrated. With the assistance of a copper wire that is wrapped by the microfiber knot, resonant wavelength inside the MKR can be tuned by applying electric current to the copper wire. The resonant wavelength change is based on the thermally induced optical phase shift in the MKR due to the heat produced by the flow of electric current over a short transit length. It is shown that the wavelength shift is linearly proportional to the square of the amount of current and the maximum tuning slope of 51.3 pm/A2 is achieved using a newly fabricated MKR.

C-Band Q-Switched Fiber Laser Using Titanium Dioxide (TiO 2 ) As Saturable Absorber

Abstract: We demonstrate a passively Q-switched erbium fiber laser using titanium dioxide (TiO 2) as a saturable absorber. The TiO 2 saturable absorber was fabricated as a polymer composite film and sandwiched between fiber ferrules. Q-switched pulsing starts with the assistance of physical disturbance of the laser cavity (by lightly tapping the cavity to induce instability) at 140 mW and lasts until 240 mW. The repetition rate increases with the pump power from 80.28 to 120.48 kHz. On the other hand, the pulsewidth decreases from $2.054\ \mu\text{s}$ until it reaches a plateau at $1.84\ \mu\text{s}$ . The Q-switched fiber laser exhibits two competing modes: at 1558.1 and 1558.9 nm as the pump power increases. A high signal-to-noise ratio of 49.65 dB is obtained.

Gain enhancement in L-band EDFA through a double-pass technique

Abstract: An improvement of gain in the long-wavelength band (L-band) is observed by double passing the forward amplified spontaneous emission and signal in the erbium-doped fiber (EDF) using a circulator, unlike conventional single pass amplification. A gain enhancement as high as 11 dB is obtained for a 1570-nm signal with an input power of -20 dBm at 98 mW of pump power. However, a noise figure penalty of about 2 dB is observed.

Generation of Mode-Locked Ytterbium Doped Fiber Ring Laser Using Few-Layer Black Phosphorus as a Saturable Absorber

Abstract: We demonstrate the generation of mode-locked pulses from a double-clad ytterbium-doped fiber laser (YDFL) employing a saturable absorber (SA) made of a few layers of black phosphorus (BP). The BP SA was prepared by mechanically exfoliating BP crystal and spreading the acquired BP flakes on a piece of scotch tape. The tape was then sandwiched between two ferrules and incorporated in a YDFL cavity to achieve a stable mode-locked operation at 1085.58 nm with a repetition rate of 13.5 MHz. A maximum pulse energy of 5.93 nJ was obtained at pump power of 1322 mW with the output power of 80 mW. Our study may well be the first demonstration of the BP-based mode-locked fiber laser that should shed some new insights into two-dimensional layer materials related photonics.

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Significant remote sensing vegetation indices: A review of developments and applications

Abstract: Vegetation Indices (VIs) obtained from remote sensing based canopies are quite simple and effective algorithms for quantitative and qualitative evaluations of vegetation cover, vigor, and growth dynamics, among other applications These indices have been widely implemented within RS applications using different airborne and satellite platforms with recent advances using Unmanned Aerial Vehicles (UAV) Up to date, there is no unified mathematical expression that defines all VIs due to the complexity of different light spectra combinations, instrumentation, platforms, and resolutions used Therefore, customized algorithms have been developed and tested against a variety of applications according to specific mathematical expressions that combine visible light radiation, mainly green spectra region, from vegetation, and nonvisible spectra to obtain proxy quantifications of the vegetation surface In the real-world applications, optimization VIs are usually tailored to the specific application requirements coupled with appropriate validation tools and methodologies in the ground The present study introduces the spectral characteristics of vegetation and summarizes the development of VIs and the advantages and disadvantages from different indices developed This paper reviews more than 100 VIs, discussing their specific applicability and representativeness according to the vegetation of interest, environment, and implementation precision Predictably, research, and development of VIs, which are based on hyperspectral and UAV platforms, would have a wide applicability in different areas