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Title: | 以碳化矽波導環/耦合器研製全光相位/強度調變器 All-optical Phase and Amplitude Modulators based on Carbon Excessive SiCx Micro-ring Resonator and Directional Coupler |
Authors: | Cai-Syuan Fu 傅才軒 |
Advisor: | 林恭如(Gong-Ru Lin) |
Keyword: | 全光調變器,非線性克爾效應,矽光子,微米環波導元件, All-optical modulator,nonlinear kerr effect,silicon photonics,micro-ring waveguide devices, |
Publication Year : | 2017 |
Degree: | 碩士 |
Abstract: | 在本文中,使用富含碳碳化矽微米環共振腔波導與定向耦合器進行了模擬,製造和分析,以達到全光強度/相位由光學非線性效應調製和全光邏輯處理。
在第2章中,使用富含碳碳化矽微米環共振腔波導通過非線性克爾效應達到10 Gbit/s的全光相位調變器將強度訊號轉置成相位訊號。對於微米環與長直波導間距為1300奈米的富含碳碳化矽微米環共振腔波導強度調變器,由非線性克爾效應引起訊號調變的訊雜比被增加到12.4 dB,由微米環波導光頻譜位移量得到其折射率變化量為1.65E-4。另外,強度調變和相位調變兩種格式可以藉由富含碳碳化矽微米環共振腔波導來執行由於在不同波長下克爾效應引起的強度變化的強度調變器或相位變化的相位調變器。使用相位訊號解調器時,脈衝輸入訊號需要經過數位邏輯處理輸入富含碳碳化矽微米環共振腔波導,通過使用編碼電路經調製的數據流可以被解調為與原始的輸入數據流,並且還通過數位邏輯電路標準,解調後的誤碼率、訊雜比及消光比為1.1E-5與4.08 dB和10.94 dB 並與商用相位調變器比較。從上述實驗中,富含碳碳化矽微米環共振腔波導經過脈衝訊號編碼調變相位調變器實現了強度訊號與相位訊號調製格式之間的轉換,此外,亦加密了輸入的調變訊號,以增加安全性,這提供了一種用於加密算法的開發的一種方法。 在第3章,對於富含碳碳化矽微米環共振腔波導自相位調變效應和群速度延遲效應之間的啾頻管理實現25 Gbit/s的脈衝歸零開關的全光強度調變。在高脈衝功率以引發富含碳碳化矽微米環共振腔波導的自相位調變效應可由12 Gbit/s、25 Gbit/s及增益調變脈衝訊號測得非線性折射率係數為2.76E-13 cm2W-1、1.026E-13和2.37E-14 cm2W-1。由全光強度轉換訊號的眼圖中得知訊雜比和消光比分別5.6 dB和11.8 dB,對應的上升和下降時間分別為20.9皮秒和21.9皮秒。此外,由全光強度反向調變序號的眼圖得知訊雜比和消光比分別4.8 dB和10.2 dB,對應的上升和下降時間分別為20.9皮秒和21.2皮秒。由微環形諧振腔波導達成25 Gbit/s全光數據轉換和反轉,其誤碼率分別為2.52E-6分別和1.13E-5。 在第4章中,我們使用微米環共振腔定向耦合器達成複雜的全光邏輯電路OR及 。藉由脈衝強度訊號“01010110”和探針偏振訊號“10001101”,證明微米環共振腔定向耦合器在探針波長為1563.10奈米可達成處理得到輸出訊號為 “11011111”。此外,當輸入微米環共振腔定向耦合器的探針波長為1563.30奈米時,探針訊號經過訊號處理為“10101101”。 12 Gbit/s強度訊號及12 Gbit/s極化訊號透過邏輯訊號處理可以實現12 Gbit/s的邏輯運算處理速度。邏輯運算機制為透過非線性克爾效應使調變頻譜紅移和有偏振選擇性的微米環定向耦合器在不同的波長可以進行不同的邏輯處理。例如探針波長為1563.10奈米,TM模態的光不會耦合進微米環內和TE模態的光則可因為脈衝訊號使其開關被打開,其可作為OR邏輯閘;而當探針波長為1563.30奈米時,TM模態的光依然不會耦合進微米環內和TE模態的光則因為脈衝訊號使其開關被關閉,其可被證明是一個複雜的邏輯閘 。其與具有邏輯積體電路相比,光學邏輯運算可以通過4通道的WDM技術使得運算處理速度可以達到積體電路的4倍。 In this thesis, the carbon excessive SiCx based micro-ring resonator waveguide and the micro-ring resonator directional coupler was simulated, fabricated and analyzed to achieve all-optical intensity/phase modulation and all-optical logic processing by optical nonlinear effect. In the chapter 2, the C-rich silicon carbide (SiCx) micro-ring resonator waveguide based 10 Gbit/s all-optical phase modulator phase shift keying (PSK) data modulation is demonstrated by using the nonlinear Kerr effect. For the C-rich SiCx micro-ring resonator waveguide intensity modulator, the SNR induced by the nonlinear Kerr effect is enhanced to 12.4 dB for the micro-ring resonator waveguide with the gap spacing increasing to 1300 nm with the group index change (ΔNg) to 1.65E-4 because the stronger ring cavity with the larger gap spacing to enhance the peak intensity induces the larger refractive index change. In addition, the conversion between the ASK and PSK modulation formats can be performed by the C-rich SiCx micro-ring resonator waveguide phase modulator because of the Kerr effect induced phase variation. Due to the demodulated mechanism of the DLI device, the input data steam needs to encode before injecting into the C-rich SiCx micro-ring resonator phase modulator, which ensures that the demodulated data steam is same as the input data steam. The modulated data stream by using the encoded circuit can be demodulated to the same as the original input data stream and also pass the CMOS criterion. The BER of the demodulated data stream with the C-rich micro-ring resonator phase modulator is obtained as 1.1E-5 with the SNR and ER of 4.08 dB and 10.94 dB, respectively, as compared to the commercial phase modulator. From the above experiments, the C-rich SiCx micro-ring resonator phase modulator with the encode data not only achieves the conversion between the PSK and ASK modulation format but also encrypts the input data to increase the security, which provides one method for the development of the encryption algorithm. In the chapter 3, the chirp management between SPM and passive GVD for a carbon excessive SiC mirco-ring waveguide is demonstrated to achieve 25 Gbps pulse return-to zero on-off keying (PRZ-OOK) data transmission. Under the high pumping power to induce the self-phase modulation (SPM) the nonlinear refractive index coefficient of carbon excessive SiC mirco-ring waveguide is obtained as 2.76E-13 cm2W-1. The nonlinear refractive index coefficients of the device are achieved as 1.026E-13 and 2.37E-14 cm2W-1, respectively, when a pumping pulse changes to 25 Gbps PRZ-OOK and gain-switched pulses. To analyze the eye diagram of data conversion, the signal-to-noise ratio (SNR) and extinction ratio (ER) are obtained as 5.6 dB and 11.8 dB with a corresponding rising and falling time of 20.9 ps and 21.9 ps, respectively. In addition, the all-optical data inversion with a data rate of 25 Gbps has a SNR of 4.8 dB and an ER of 10.2 dB with a rising and falling time of 20.9 ps and 21.2 ps, respectively. The bit-error rates (BERs) of all-optical data conversion and inversion with a data rate of 25 Gbps by the micro-ring resonator waveguide are achieved to 2.52E-6 and 1.13E-5, respectively. In the chapter 4, The complex all-optical logic gate is demonstrated on the simple directional coupler with the micro-ring resonator. With the pulsed ASK data stream of “01010110” and the polarized PolSK probe stream of “10001101”, the device has been demonstrated as a logical OR gate with the probe wavelength at 1563.10 nm, which the data stream with the logical processing is “11011111”. On the other hand, the device has been demonstrated as a complex logical gate with the probe wavelength at 1563.30 nm, which the logical processed data stream is demonstrated to “10101101”. With the pulsed ASK data stream of the data rate 12 Gbps and the PolSK probe stream of the data rate 12 Gbps, the logical data processing can follow the data rate of the pulsed pump and PolSK probe inputs to achieve 12 Gbps processing speed. The logical process is modulated with the spectral comb red-shifted by nonlinear Kerr effect and the polarization sensitive of the micro-ring directional couple at different wavelength. For the probe wavelength is set at 1563.10 nm, the TM-mode do not couple into the micro-ring and the TE-mode can be switch on with the pulsed pump, which can be demonstrated as a logical OR gate. In addition to the probe wavelength of 1563.30, the probe is out of the spectral TM transmission dip and the TE-mode can be converted to the inversion bit with the pulsed pump, which can be demonstrated as a complex logical gate. With a logic OR gate and a complex logical gate, the micro-ring directional coupler can be port of the optical computing to build up integrated optical circuit which can achieve complex usage. Compare to the integrated circuit, the optical circuit can process by WDM technique with 4 channel that the processing speed can achieve the as 4 times as which of the integrated circuit. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/20323 |
DOI: | 10.6342/NTU201704462 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 光電工程學研究所 |
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