本論文對光子晶體L3共振腔、雙重L3共振腔的共振模態與光輻射特性進行研究。利用微光激發螢光(μ-PL)光譜對共振模態進行觀察，並以二維平面波展開法與三維有限時域差分法兩種模擬方式進行模擬。將實驗與模擬結果做比較，結果顯示若改變空氣孔柱半徑與晶格常數的比值(R/a)，則共振波長會變化，也會產生新的共振模態。在雙重L3共振腔的μ-PL光譜中發現最長波長的兩個模態，其耦合強度隨著共振腔間的空氣孔柱排數(n)增加而減少。在目前各種微共振腔的研究結果中，n=1的雙重L3共振腔具有很高的耦合強度。在本實驗的結果中，品質因子約為790-1530，沒有發現如文獻所述品質因子會隨耦合強度增加而減少的相對關係。在量子點薄片上製作光子晶體結構後，使得量子點的螢光在光輸入輸出曲線(對數關係曲線)中的斜率，A系列試片由1.12上升至1.53，B系列試片由1.32上升至1.81，推測是受到蕭克利-里德-霍爾復合(Shockley-Read-Hall recombination)影響。In this thesis, the resonant modes and radiative properties of L3 cavity and double L3 cavity were studied. The resonant modes were observed by micro-photoluminescence(μ-PL) spectroscopy. Two kinds of simulations were used: two-dimensional plane wave expansion method (2D PWEM) and three-dimensional finite-difference time-domain method (3D FDTD method). Then the information of experiments and simulations were compared. The results show that the wavelength of each resonant mode is changed and a new resonant mode is generated if the ratio of air holes’ radius and lattice constant are changed. The coupling strength of the resonant modes of two longest wavelength in the spectrum of double L3 cavity is decreased as the number of air-hole layers increasing. Compared with the other microcavities has been reported, the coupling strength in 90 degree double L3 cavity with n=1 is extremely high. In this experiment, the observed quality factor is around 790-1530. The tendency that quality factor is higher with larger n  did not observed in this study. The slope in L-L curve (log-log scale) would be increased from 1.12 to 1.53 in A series and from 1.32 to 1.81 in B series after the photonic crystal structure being fabricated at quantum dots’ slab. It may be deduced by the Shockley-Read-Hall recombination.