ORCID Profile
0000-0002-4599-6353
Current Organisations
SeedNanoTech International Inc.
,
GEM Systems Inc.
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Publisher: MDPI AG
Date: 15-01-2019
DOI: 10.20944/PREPRINTS201901.0148.V1
Abstract: This paper reports 2 × 4 hybrid Mach-zehnder interferometer (MZI) - multi-mode interferometers (MMI) based compact thermo-optical switch consisting of slab waveguides on silicon-on-insulator, SOI, platform. The device consists of two identical MMIs, each of 6 μm wide and 140 μm long connected with two phase shifters MMIs each with 2 μm wide and 8 μm long and linear tappers each 4 μm long, connected at both ends of the MMIs to minimize the power coupling loss. The loss for linear taper is found to be below 0.02dB. The footprint of the whole device is six 6 μm × 324 μm. This structure is based on unique multimode region shape, which leads optical switch to have less coupling loss and reduced cross-talk. The average thermo-optical switching power consumption is 1.4 mW, the excess losses are 0.8 dB, and the imbalances are 0.1 dB. Aluminum is used as a heating pad, and a trench is created around this pad to prevent from spreading of heat and reduce power loss almost by a factor of 2 to the adjacent phase shifter. Our new heating method has advantages of compact size and ease of fabrication with the current CMOS technology.
Publisher: MDPI AG
Date: 28-10-2018
Abstract: A series of Eu3+ doped CaSiO3/SiO2 nano-phosphor powder of controlled grain size, crystalline structure, and chemical composition were synthesized using the microemulsion technique. The morphology, size, and shape of the synthesized nanophosphorous powder were investigated using transmission electron microscopy and X-ray diffraction (XRD) analysis. XRD profiles of s les sintered over 600 °C, suggested phase shift from amorphous powder grain to more ordered polycrystalline powder of triclinic type wollastonite, CaSiO3, with preferred crystal phase orientation of (112) and tetragonal type cristobalites of SiO2. The grain size, crystallinity, and chemical composition of the host matrix, activator and sensitizer strongly affected both the absorption and emission bands of these s les. The litude of both the orange and red emission bands significantly increased with sintering temperature. The emission band is red-shifted with decreasing grain sizes. These bands displayed good sensitivity to ionic concentration of the Si4+, Ca2+, and Eu3+. With increasing Ca2+ ion concentration both the intensity of the red photoluminescence (PL) band increased and a concentration quenching observed. Increase in Si4+ ion concentration led to quenching in PL intensity of both the orange and red bands, whereas the litude of the blue-band slightly increased. With increasing Eu3+ ion concentration the red-band initially increased whereas it started decreasing at higher s le concentration. In the presence of Ca2+ ion as a sensitizer, the s le showed a remarkable PL property-including–about 100% photon conversion efficiency and a two-fold increase in excitation and emission photons.
Publisher: MDPI AG
Date: 19-09-2018
DOI: 10.20944/PREPRINTS201809.0376.V1
Abstract: A series of Eu3+ doped CaSiO3/SiO2 nano-phosphor powder of controlled grain size, crystalline structure, and chemical composition were synthesized using the microemulsion technique. XRD profiles of s les sintered over 600 of suggested phase shift from amorphous powder grain to more ordered polycrystalline powder of triclinic type wollastonite, CaSiO3, with preferred crystal phase orientation of (112) and tetragonal type cristobalites of SiO2. The grain size, crystallinity, and chemical composition of the host matrix, activator and sensitizer strongly affected both the absorption and emission bands of these s les. The litude of both the orange and red emission bands significantly increased with sintering temperature. The emission band is red-shifted with decreasing grain sizes. These bands displayed good sensitivity to ionic concentration of the Si4+, Ca2+, and Eu3+. With increasing Ca2+ ion concentration both the intensity of the red photoluminescence (PL) band increased and a concentration quenching observed. Increase in Si4+ ion concentration led to quenching in PL intensity of both the orange and red bands whereas the litude of the blue-band slightly increased. With increasing Eu3+ ion concentration the red-band initially increased whereas it started decreasing at higher s le concentration. In the presence of Ca2+ ion as a sensitizer, the s le showed a remarkable PL property& mdash including& mdash about 100% photon conversion efficiency and a two-fold increase in excitation and emission photons.
Publisher: MedCrave Group, LLC
Date: 04-2016
Publisher: MDPI AG
Date: 12-06-2019
DOI: 10.3390/MA12091555
Abstract: This paper reports design of a 2 × 4 hybrid multimode interferometer-Mach-zehnder interferometer (MMI-MZI) configuration consiting of compact thermo-optical switches on the silicon-on-insulator (SOI) platform. The device consists of two identical MMI slab waveguides as power splitters and couplers that are connected with two identical MMI-based phase shifters, and linear tapers at both ends of the MMIs to minimize the power coupling loss. A thin Al pad is used as a heating element and a trench is created around this pad to prevent heat from spreading, and to minimize loss. The calculated average thermo-optical switching power consumption, excess loss, and power imbalance are 1.4 mW, 0.9 dB, and 0.1 dB, respectively. The overall footprint of the device is 6 × 304 μ m 2 . The new heating method has advantages of compact size, ease of fabrication on SOI platform with the current CMOS technology, and offers low excess loss and power consumption as demanded by devices based on SOI technology. The device can act as two independent optical switches in one device.
Location: United States of America
No related grants have been discovered for Conrad Rizal.