本研究以Folded Šolc Filter為基礎所設計出的偏振旋轉器結構，以在矽波導中蝕刻週期性的左右空氣方孔來達到雙折射的效果，其結果會與左右交替方位角的Folded Šolc Filter相似。我們使用了有限時域差分法、光束傳播法及三維特徵模態展開法等方法，成功模擬出在極微小的元件長度(約9.21 µm)下達到高偏振旋轉反射率的成果(最高可達到的反射率為93.1%)，可操作的波長範圍約為1460.4nm至1619.4nm，涵蓋光通訊所使用的光譜範圍從S-band(1460-1530nm)、C-band(1530-1565nm)到L-band(1565-1625nm)，並透過計算其能帶結構來確認波導反射頻譜中的波峰是由光子能隙所造成的。期望本元件可應用於量子光學電腦中的邏輯計算中。;In this thesis, we designed a polarization rotator based on the Folded Šolc Filter that can possess birefringence by etching periodically-arranged alternatively-shifted air holes in a silicon waveguide. We obtain the reflective polarization rotator with high reflectivity with an extremely small device length (approximately 9.21 µm) using the methods including the finite-difference time-domain method, the beam propagation method, and the three-dimensional eigenmode expansion method. The highest achievable reflectivity was 93.1%, with an operation bandwidth from 1460.4nm to1619.4nm, which covers the S-band (1460-1530 nm), C-band (1530-1565 nm), and L-band (1565-1625 nm) of optical communication spectrum. By calculating the band structure, we confirmed that the peaks in the reflection spectrum were caused by photonic bandgaps. This device could be applied for optical quantum computing.
