| Summary: | 碩士 === 國立中山大學 === 光電工程研究所 === 97 === As the photonic crystal fibers (PCFs) are fabricated, it is hard to modulate their optical characteristics to function as tunable optical devices. To introduce tunable optical characteristics into the PCF structures, one can infiltrate liquids into the air holes of the PCFs to form the liquid-filled PCFs. However, the propagation losses become larger due to the
finite liquid-hole layers and the lossy liquids infused in all the air holes of the cladding. In this thesis, an efficient full-vector finite-difference frequency-domain (FDFD) mode solver cooperated with the PMLs is utilized to investigate the propagation characteristics of the selectively liquid-filled PCFs. The propagation constants and the propagation losses of the
guided modes on the selectively liquid-filled PCFs can be successfully obtained. From our numerical results, the propagation losses of both the internally liquid-filled PCFs and externally liquid-filled PCFs can be efficiently reduced by the outer or inner air-hole layers, and the useful tunablility characteristics for optical device applications can be maintained.
Besides, the dispersion-related devices based on the selectively liquid-filled PCFs are also investigated. It is demonstrated that a DFPCF with the flatten dispersion value D within 0 ± 1 ps/nm/km over λ = 1.45 μm to 1.65 μm or a DCPCF with a high negative dispersion value D = -3100 ps/nm/km at λ = 1.55 μm can be achieved by infiltrating the liquid into all air holes or specified air-hole layers.
In the experiment, a simple selectively blocking technique using the microscopy, the tool fiber and the alignment technique is employed to fabricate the internally and externally liquid-filled PCFs. The measurement of the optical characteristics of these selectively liquid-filled PCFs is carried out and compared with the simulation results.
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