Browsing by Author "R. Jomtarak"
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Item All-optical logic and and or gates generated by dark-bright soliton conversion(2013) P. Phongsanam; C. Teeka; R. Jomtarak; S. Mitatha; P.P. Yupapin; P.P. Yupapin; Advanced Research Center for Photonics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand; email: kypreech@kmitl.ac.thIn this paper, a novel system of simultaneous optical logic AND and OR gates using dark-bright soliton conversion within the add/drop optical filter system is proposed. By using the dark-bright soliton conversion concept, the switching output signal response time of ns can be obtained. The input logic '0' and control logic '0' are formed by using the dark soliton pulse (D) trains. We found that the simultaneous optical logic AND and OR gates at the drop and through ports can be formed, respectively. The comparison data of the commercial system is also given, which is shown that the proposed system has the advantage over the commercial ones. © 2012 Elsevier GmbH. All rights reserved.Item All-optical switches based-on GaAs/AlAs quantum dots vertical cavities(Elsevier Ltd, 2012) C. Teeka; R. Jomtarak; P. P. Yupapin; C. Teeka; Scientific Equipment Center, Faculty of Science and Technology, Suan Dusit Rajabhat University, Bangkok, 10700, Thailand; email: chat_tee@dusit.ac.thIn this paper, we present an all-optical switch based on self-assembled GaAs/AlAs quantum dots (QDs) within a vertical cavity. Two essential aspects of this novel device have been investigated, which includes the QD/cavity nonlinearity with appropriately designed mirrors and the intersubband carrier dynamics inside QDs. Verticalreflection- type switches have been investigated with an asymmetric cavity that consists of 12 periods of GaAs/Al0.8Ga0.2As for the front mirror and 25 periods for the back mirror. The thicknesses of the GaAs and AlGaAs layers are chosen to be 89 and 102 nm, respectively. To give a dot-in-a-well (DWELL) structure, 65nm dimension of Si was deposited within an 20nm AlAs QW. All-optical switching via the QD excited states has been achieved with a time constant down to 750 fs, wavelength tunability over 29.5 nm. These results demonstrate that QDs within a vertical cavity have great advantages to realize low-power consumption polarization-insensitive micrometer-sized switching devices for the future optical communication and signal processing systems. © 2010 Published by Elsevier Ltd.Item ASK-to-PSK generation based on nonlinear microring resonators coupled to one MZI arm(2011) C. Teeka; S. Songmuang; R. Jomtarak; P.P. Yupapin; M.A. Jalil; I.S. Amiri; J. Ali; C. Teeka; Scientific Equipment Center, Faculty of Science and Technology, Suan Dusit Rajabhat University, Bangkok 10700, Thailand; email: chat_tee@dusit.ac.thWe present a new concept of ASK-to-PSK generation based on nonlinear microring resonators coupled to one MZI arm by using OptiWave FDTD method. By microring resonator increase from one to three microring (SR to TR), we found that the amplitude shift keying (ASK) are increase exactly and the phase shift keying (PSK) is equal to ¹. © 2011 American Institute of Physics.Item ASK-to-PSK generation based on nonlinear microring resonators coupled to one MZI arm(2011) C. Tanaram; C. Teeka; R. Jomtarak; P.P. Yupapin; M.A. Jalil; I.S. Amiri; J. Ali; C. Tanaram; Faculty of Science and Technology, Kasem Bundit University, Bangkok 10250, Thailand; email: tchanapk@gmail.comWe present a new concept of ASK-to-PSK generation based on nonlinear microring resonators coupled to one MZI arm by using OptiWave FDTD method. By microring resonator increase from one to three microring (SR to TR), we found that the amplitude shift keying (ASK) are increase exactly and the phase shift keying (PSK) is equal to ¹.Item Geometrically distributed 1D photonic crystals for light-reflection in all angles(Elsevier Ltd, 2012) R. Jomtarak; C. Teeka; P. P. Yupapin; R. Jomtarak; Nanoscale Science and Engineering Research Alliance (n'Sera), Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand; email: rangsan_jom@dusit.ac.thIn this paper, we presented the general formulation of light reflection using a series of 1D PCs with different periods, made of non-absorptive materials of any refractive indices. In order to have a large bandgap - the spectral range of reflection, the periods of 1D PCs must be distributed in a geometrical progression with a common ratio, r, smaller than a maximum value of rc. The paper have presented exact expressions for rc, bandgap to mid gap ratio of the PC hetero-structure, and the minimum number of PCs to achieve the desired range of bandgap in single and all angles of incidence. The proposed method can be used to design filters for vast range of applications such as UV filters (i.e., sunglasses, eye safety glasses, UV photography filters) and visible light filters. © 2010 Published by Elsevier Ltd.Item Single electron-hole pair generation using dark-bright solitons conversion control(2011) R. Jomtarak; C. Teeka; P.P. Yupapin; J. Ali; R. Jomtarak; Advanced Research Center for Photonics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand; email: rangsan_jom@dusit.ac.thIn this paper, we present the new concept of single electron-hole pair generation by using dark-bright solitons conversion control based on microring resonator coupled to one arm MZI. By using some suitable parameters and found that the single electron-hole pair are seen, therefore, the single electron-hole pair generate can be storage and controll within the design system. © 2011 American Institute of Physics.Item Single electron-hole pair generation using dark-bright solitons conversion control(2011) S. Punthawanunt; R. Jomtarak; C. Teeka; P.P. Yupapin; J. Ali; S. Punthawanunt; Faculty of Science and Technology, Kasem Bundit University, Bangkok 10250, Thailand; email: suphanchai@kbu.ac.thIn this paper, we present the new concept of single electron-hole pair generation by using dark-bright solitons conversion control based on microring resonator coupled to one arm MZI. By using some suitable parameters and found that the single electron-hole pair are seen, therefore, the single electron-hole pair generate can be storage and controll within the design system.Item Single electron-hole pair generation using dark-bright solitons conversion control(2010) R. Jomtarak; C. Teeka; P.P. Yupapin; J. Ali; R. Jomtarak; Advanced Research Center for Photonics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand; email: rangsan_jom@dusit.ac.thRecently, the electron-hole pair generated in 1.06-_m separate-absorber-avalanche (multiplier) InP-based devices [1], SiGe/Si planar waveguides [2] fabricated with a Ge concentration ranging from 2% to 6% and different thicknesses ranging from 200 nm to 2 _m, generating electron-hole pairs with a 100 fs laser pulse emitted at 810 nm, and monitoring the free-carrier absorption transient with a c.w. probe beam at 1.55 _m, bipolar transistors [3], CMOS process [4], InAs-GaSb superlattice (SL) photodiodes [5], resonant microcavity [6], A cavity-QED using a single InAs quantum dot and a high-Q whispering gallery mode [7]. ©2010 IEEE.