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Abstrak :
ABSTRAK
Divais directional coupler dan optical switch merupakan komponen yang dibutuhkan dalam pemrosesan sinyal optik. Kemajuan teknologi wavelength division multiplexing (WDM) dan pertumbuhan lalu lintas internet yang cepat memicu banyak penelitian tentang teknologi switching optik. Galium Nitrida (GaN) merupakan material semikonduktor nitrida kelompok III yang menjadi kandidat menjanjikan untuk divais yang beroperasi pada panjang gelombang komunikasi optik. Pada penelitian ini dilakukan desain directional coupler dan optical switch menggunakan material GaN untuk panjang gelombang telekomunikasi, yaitu 1,55 um. Desain directional coupler terdiri dari pandu gelombang S-bend dan linear sedangkan desain optical switch berbasis Mach-Zehnder Interferometer yang terdiri dari dua directional coupler yang dihubungkan dengan dua lengan persegi panjang. Optimasi desain dilakukan dengan metode finite difference beam propagation method (FD-BPM) menggunakan perangkat lunak OptiBPM. Optimasi dilakukan dengan memvariasikan parameter pandu gelombang meliputi lebar, ketebalan, width gap dan coupling gap. Dari hasil simulasi ditunjukkan bahwa lebar dan tebal terbaik untuk memperoleh propagasi single mode masing-masing adalah 4 um. Selanjutnya, berdasarkan hasil optimasi ukuran pandu gelombang dilakukan desain directional coupler dan optical switch. Ditunjukan bahwa directional coupler dengan panjang 980 um dan lebar 15 um dengan width gap 7 um dan coupling gap 6 μm menghasilkan daya keluaran sebesar 91,71% dengan splitting ratio sebesar 48,83% : 48,03%, excess loss dan power imbalance berturut-turut sebesar 0,37 dB dan 0,07 dB. Tahap selanjutnya, berdasarkan lebar dan tebal pandu gelombang, dilakukan optimasi desain optical switch. Dari hasil eksperimen numerik ditunjukkan bahwa desain optical switch terbaik, memiliki panjang 6380 μm dan lebar 15 um, dengan panjang elektroda sebesar 4500 μm. Optical switch mampu beroperasi sebagai switch pada
 = 34 V dengan insertion loss dan extinction ratio berturut-turut sebesar 1,23 dB dan 8,46 dB

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ABSTRACT
Directional coupler and optical switches are the components needed in optical signal processing. The progress of wavelength division multiplexing (WDM) technology and the rapid growth of internet traffic have triggered much research regarding optical switching technology. Gallium Nitride (GaN) is a III-nitride semiconductor becomes a promising candidate for devices which operate in wavelength optical communications. In this research, the design of GaN-based directional coupler and optical switch design was conducted for telecommunication wavelength at 1.55 um. The design of directional coupler consists of S-bend and linear waveguide, whereas, design of optical switch based on Mach-Zehnder Interferometer consists of two directional couplers connected by two rectangular arms. Design optimization was conducted by finite difference beam propagation method (FD-BPM) using OptiBPM software. Optimization was conducted by a varying waveguide parameter such as waveguide width, waveguide thickness, width gap and coupling gap. From the simulation results, the best of width and thickness were 4 um and 4 um, respectively, for support single-mode propagation. Next, based on the optimization result of the waveguide dimension, it was conducted a design of the directional coupler and optical switch. It was noticed that the directional coupler was 980 m long, and 15 um wide with width gap and coupling gap were 7 um and 6 μm, respectively. It generated the output power of 91.71% with the splitting ratio of 48.83 %: 48.03% while the excess loss of 0.37 dB and the power imbalances of 0.07 dB. The next step, optimization of the optical switch design was conducted based on the width and thickness of the waveguide. From the simulation result, the best design of the optical switch was 6380 μm long and 15 um wide, with the electrode length was 4500 μm. The optical switch could operate as an optical switch at = 34V with an insertion loss of 1.23 dB and an extinction ratio of 8.46 dB.

Abstrak :
ABSTRACT
A good justification for gallium nitride on silicon is a potential for optoelectronic integrated circuits, and its low cost has stimulated the growth of GaN on large size wafers. The application interest for GaN/Si is power electronics. This current work focuses on characterization optical, electro-optical, and microstructural and simulation design of GaN/Si channel waveguide. For the characterization of GaN microstructure, we use SEM, TEM, AFM, and XRD to observe layer thickness, material structure, material roughness, and crystalline quality of materials. Using the guided wave prism coupling technique, we have fully established the index dispersion and, thickness of GaN at room temperature, as well as its surface roughness based on AFM characterization. Futhermore, the thermal dependence of GaN at ordinary and extraordinary refractive indices are determined to be at 1.227 10-5/ K and 1.77 10-5/ K, respectively. The thermal dependence of GaN shows better value than GaAs at the wavelength range of 0.4 - 1.5 m. It has a slightly low-temperature dependence. Results demonstrate that excellent waveguide properties of GaN on silicon with an optical propagation loss of GaN/Si at 633 nm is 2.58 dB/cm, which is higher than the propagation loss of GaN/sapphire at around 1.34 dB/cm. The roughness of GaN/Sapphire and GaN/Si samples have been identified at the range 1.6 - 5.2 nm and 9.6 - 13 nm, respectively. The birefringence of GaN/Si is negative within the range of -0.16 x10-2 to -6.06x10-2. This negative value means that the polarization of the wave is parallel to the optical axis. Electrooptic constants r13 = 1.01 pm/V and r33 = 1.67 pm/V are higher than those obtained for III-V GaAs semiconductors. We compared the results on Si with those on sapphire. Based on a numerical simulation using OptiBPM, the design result has single mode output with 1 m thickness layer of SiO2 at the planar waveguide design, while the channel waveguide design has 1 m thickness layer of GaN. The simulated result that the maximum power output approximately 50- 58 at the plannar and rib waveguide design.

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ABSTRAK
A good justification for gallium nitride on silicon is a potential for optoelectronic integrated circuits, and its low cost has stimulated the growth of GaN on large size wafers. The application interest for GaN Si is power electronics. This current work focuses on characterization optical, electro optical, and microstructural and simulation design of GaN Si channel waveguide. For the characterization of GaN microstructure, we use SEM, TEM, AFM, and XRD to observe layer thickness, material structure, material roughness, and crystalline quality of materials. Using the guided wave prism coupling technique, we have fully established the index dispersion and, thickness of GaN at room temperature, as well as its surface roughness based on AFM characterization. Futhermore, the thermal dependence of GaN at ordinary and extraordinary refractive indices are determined to be at 1.227 10 5 K and 1.77 10 5 K, respectively. The thermal dependence of GaN shows better value than GaAs at the wavelength range of 0.4 1.5 m. It has a slightly low temperature dependence. Results demonstrate that excellent waveguide properties of GaN on silicon with an optical propagation loss of GaN Si at 633 nm is 2.58 dB cm, which is higher than the propagation loss of GaN sapphire at around 1.34 dB cm. The roughness of GaN Sapphire and GaN Si samples have been identified at the range 1.6 5.2 nm and 9.6 13 nm, respectively. The birefringence of GaN Si is negative within the range of 0.16 x10 2 to 6.06x10 2. This negative value means that the polarization of the wave is parallel to the optical axis. Electrooptic constants r13 1.01 pm V and r33 1.67 pm V are higher than those obtained for III V GaAs semiconductors. We compared the results on Si with those on sapphire. Based on a numerical simulation using OptiBPM, the design result has single mode output with 1 m thickness layer of SiO2 at the planar waveguide design, while the channel waveguide design has 1 m thickness layer of GaN. The simulated result that the maximum power output approximately 50 58 at the plannar and rib waveguide design.

Abstrak :
Recently, gallium nitride (GaN) material has attracted the attention of researchers as a candidate for third generation semiconductor material for optical telecommunication applications. In this research, a 2x2 multimode interference optical power splitter (MMI) based on a waveguide and ridge structure is proposed using gallium nitride material on a silicon (GaN/Si) substrate for optical telecommunication applications. The design optimization carried out resulted in two optical power splitter designs based on rib (design A) and ridge (design D) waveguide. Based on the simulation using the eigenmode expansion method (EME) algorithm, design A has an optimal dimension of 15 m 212 m with an insertion loss of 0.085 dB, power balancing of 0.007 dB, C-band (1530 nm – 1565 nm) broadband bandwidth of 0.140 dB, and fabrication tolerances for width and length are ± 0.3 m and ± 0.5 m, respectively. Meanwhile, design D has optimal dimensions of 15 m 214 m with insertion loss of 0.036 dB, power balancing of 0.017 dB, C-band broadband bandwidth of 0.088 dB, and fabrication tolerances for width and length respectively. of ± 0.3 m and ± 0.5 m

Abstrak :
The AlInGaN and ZnO materials systems have proven to be one of the scientifically and technologically important areas of development over the past 15 years, with applications in UV/visible optoelectronics and in high-power/high-frequency microwave devices. The pace of advances in these areas has been remarkable and the wide band gap community relies on books like the one we are proposing to provide a review and summary of recent progress.