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A reliable Nd:YAG laser welded stainless steel 304 for photonics device packaging application
(2011-05-02)
Nawi, I. N.
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Saktioto
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Fadhali, M.
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Hussain, M. S.
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Ali, J.
An ultra compact pulsed Nd:YAG laser with laser beam peak power of 3.5 kW and 6.5 ms pulse duration is employed to produce a butt joint and lap joint for both spot and seam welding on a stainless steel 304 specimen. The strength test of the weld joints is conducted by pulling the joint materials using INSTRON Series IX/s Automated Materials Tester System. From the experimental results, it is found that a butt joint produces much stronger attachment than a lap joint. The stronger attachment is contributed by a larger volume of welded stainless steel 304 at the joint interfaces. However, the strength of a lap joint can be increased by producing a deeper weld penetration depth. It is done by controlling the laser beam parameters such as laser peak power and pulse duration. It is inferred that the commercial welding material, InvarTM, provides more robust joint than stainless steel 304. It is also concluded that the welded stainless steel 304 cannot attain the strength and elastic modulus of the stainless steel 304 itself. However, the stainless steel 304 is a good welding material for photonics device packaging by using pulsed Nd:YAG laser welding technique.
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Nd:YAG laser welding of stainless steel 304 for photonics device packaging
(2011-05-02)
Nawi, I. N.
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Saktioto
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Fadhali, M.
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Hussain, M. S.
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Ali, J.
Although pulsed Nd:YAG laser welding has been widely used in microelectronics and photonics packaging industry, a full understanding of various phenomena involved is still a matter of trials and speculations. In this research, an ultra compact pulsed Nd:YAG laser with wavelength of 1.064 μm has been used to produce a spot weld on stainless steel 304. The principal objective of this research is to examine the effects of laser welding parameters such as laser beam peak powers, pulse durations, incident angles, focus point positions and number of shots on the weld dimensions: penetration depth and bead width. The ratio of the penetration depth to the bead width is considered as one of the most critical parameters to determine the weld quality. It is found that the penetration depth and bead width increase when the laser beam peak power, pulse duration and number of shot increase. In contrast, the penetration depth decreases when the laser beam defocus position and incident angle increase. This is due to the reduction of the laser beam intensity causing by the widening of the laser spot size. These experimental results provide a reference on an optimal laser welding operations for a reliable photonics device packaging. The results obtained shows that stainless steel 304 is suitable to be used as a base material for photonics device packaging employing Nd:YAG laser welding technique.
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Thermodynamic equilibrium for nitrogen species discharge: Comparison with global model
(2011-03-01)
Ismail, F. D.
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Saktioto, T.
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Fadhali, M.
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Yupapin, P. P.
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Qindeel, R.
The equilibrium process of plasma nitrogen species by chemical kinetic reactions along various pressures is successfully investigated. The equilibrium process is required in industrial application to obtain the stable condition when heating up the material for having homogenous reaction. Nitrogen species densities is modeled by a continuity equation and extended Arrhenius form. These equations are used to integrate the change of density over the time. The integration is to acquire density and the reaction rate of each reaction where temperature and time dependence are imposed. A comparison is made with global model within pressure range of 1-100 mTorr and the temperature of electron is set to be higher than other nitrogen species. The results show that the chemical kinetic model only agrees for high pressure because of no power imposed; while the global model considers the external power along the pressure range then the electron and nitrogen species give highly quantity densities by factor of 3-5. © 2010 Elsevier GmbH. All rights reserved.
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Development of single mode fiber coupling coefficient using kinetic model
(2010-12-01)
Phattaraworamet, T.
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Saktioto, T.
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Ali, J.
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Fadhali, M.
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Yupapin, P. P.
We propose a simple kinetic model that can be used to improve the coupling coefficient value of a single mode fiber coupler in the fabrication process. The proposed model is time independent, where the internal and external parametric functions are included. The simulation is integrated over the coupling ratio range for the various fiber separations. The coupling coefficient value of the device is examined by using the coupling ratio range from 1% to 75%. The result obtained is compared with the experimental results, where it is noted that the separation of fiber cores significantly affects the coupling coefficient, exhibiting exponential behavior. We also found that the coupling coefficient gradient is significantly changed with respect to the coupling ratio. This model can be used to determine power losses of the fiber coupler at the coupled region, while the fabrication of the fiber coupler is operated. © 2009 Elsevier GmbH.
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Tunable coupling ratio for optical switch application
(2010-12-01)
Saktioto
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Hanim, Nor Faridah
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Fadhali, M.
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Yupapin, Preecha
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Ali, Jalil
This paper describes the breakdown voltage of SiO<inf>2</inf> fiber using Pockel's effect and empirical equation. The model is evaluated by coupling coefficient and refractive index changes. A 1×2 single-mode directional coupler switch has been fabricated. A large electro-optic effect causes a change in the optical properties when a slowly varying electric field is applied. A model to describe the breakdown voltage for driving the optical switch of the fusion SiO<inf>2</inf> fiber coupler has been developed. A voltage is applied through sectioned electrodes along the coupling length. This model uses the coupling coefficient and the changes in the refractive index to describe the optical switching. The change of refractive index due to the linear electro-optic Pockel effect and an empirical equation are used to calculate the value of coupling coefficient. The result shows that the changes of the refractive index increases exponentially as a function of separation fiber axis from 5 to 8 μm. The breakdown voltage and refractive indices difference depict a linear relationship. The increment of coupling coefficient shows that the value of voltage is reduced. © 2010 SPIE.
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Effect of separation length on dual fibre Bragg gratings
(2010-12-01)
Nafisah, S.
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Saktioto
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Fadhali, M.
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Yupapin, P. P.
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Ali, J.
This paper will investigate the transmission series of dual FBGs when the separation length between two FBGs is varied from 0.5 cm to 5.5 cm. The transfer matrix 2×2 is applied to complete the work. The introduction of separation length affects the transmission spectrum, indicated by the numbers of minimum dip values. Result shows that increasing the separation length between two FBG's lead to the formation of phase shift and increases the number of minimum transmission dip. © 2010 SPIE.
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External disturbance of potential energy photon in fiber Bragg grating
(2010-12-01)
Hairi, Haryana Mohd
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Saktioto
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Fadhali, M.
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Yupapin, P. P.
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Ali, Jalil
The effect of nonlinear parametric known as alpha (α), beta (β) and gamma (γ) has been successfully calculated and a new effect of theta (θ) is introduced to describe the motion of photon in a fiber Bragg grating as a factor of external disturbance. This study is developed under Bragg resonance condition where the initial frequency of the light, ω<inf>0</inf> is the same value as the Bragg frequency, ω<inf>B</inf>. We found that the potential well is not symmetric and conserved. © 2010 SPIE.
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Characterization of coupling power for single-mode fiber fusion
(2010-10-01)
Saktioto, T.
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Ali, J.
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Yupapin, P. P.
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Fadhali, M.
Fabrication of single-mode fiber coupler by heating fibers on a flame is very common and popular. However, controlling the input and the output power quantities of the fiber coupling process is neither easy nor similar. Power losses occur at the coupling length as the effect of the geometry and structure of fibers during and after fusion. In application, the power losses will affect sensor devices, e.g. optical switch. This paper proposes power splitting into the second fiber junction as a new model by deriving and integrating the coupling power with two conditions of refractive index changes. First is the change in the vertical part and second is the change in the vertical and the horizontal parts. Both conditions are studied by perpendicular and parallel directions of coupling power. The model is examined with a linear change of refractive index where power absorption and reflection are accumulated by power losses. The result shows that power increases as the effect of losses by simulation. These power losses are lost by radiation out of cladding and fiber heating. © 2009 Elsevier GmbH.
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Multi-photons trapping stability within a fiber bragg grating for quantum sensor use
(2010-01-01)
Hairi, H. M.
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Saktioto, T.
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Nafisah, S.
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Fadhali, M.
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Qindeel, Rabia
We propose an interesting result of the trapped multi photons distribution within a fiber Bragg grating. The trapped photons are confined by the potential well, which introduce the motion of photons in a fiber Bragg grating affected by multi perturbations. The external perturbations are defined as series of nonlinear parametric in terms of potential energy. This investigation is developed by using the nonlinear couple mode equations and under Bragg resonance condition where the initial frequency of the light, ω<inf>0</inf> is the same value as the Bragg frequency, ω<inf>B</inf>. The results show that the higher perturbation series represents the potential well is much indifferent of equilibrium. In applications, the perturbation can cause the trapped photons instability which introduces the escape photons from the potential well. The applications such as entangled photon source and quantum sensors can be performed.
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Nonlinear parametric studies of photon in a Fiber Bragg grating
(2009-12-16)
Saktioto
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Hairi, H. M.
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Ali, J.
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Fadhali, M.
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Yupapin, P. P.
This paper describes the effect of alpha, α and gamma, γ changes to the motion of photon in a Fiber Bragg Grating. The study has been successfully performed under Bragg resonance condition where the initial frequency of the light, ω<inf>0</inf> has the same value with the Bragg frequency, ω<inf>B</inf>. The Stokes parameter is chosen to provide important information about the total energy and energy difference between the forward and backward propagating modes. The motion of a particle moving is shown with the classic anharmonic potential where the beta, β is set to zero due to power conservation along the grating structures. © 2009 IEEE.

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