本篇論文中，我們主要以光激發螢光光譜(photoluminescence, PL)及光反射調制光譜(photoreflectance, PR)量測技術探討應力補償型鍺/矽0.15鍺0.85(Ge/Si0.15Ge0.85)多重量子井之光學特性。從溫度相依光激發螢光光譜實驗結果中，可以觀察鍺量子井的直接復合與間接復合的放光現象，同時探討兩者之間競爭性的發光復合機制。在高於室溫之溫度相依光激發螢光光譜實驗結果中，L點的載子受到熱躍至Γ點再以直接復合型式發光，此發光強度隨溫度升高而增強。另外我們利用光反射調制光譜觀測到量子井中的光學躍遷訊號。而在高於室溫之溫度相依光反射調制光譜實驗結果中，計算了鍺量子井躍遷訊號的與溫度依存性，與光激發螢光光譜之實驗結果相似，並且估算輕電洞(Light Hole)與重電洞(Heavy Hole)受應力影響而分裂的差異量。 A detailed optical characterization of strain-compensated Ge/Si0.15Ge0.85 multiple-quantum-well (MQW) structures was carried out by using photoluminescence (PL) and photoreflectance (PR) measurements. PL of strain-compensated Ge/Si0.15Ge0.85 MQW structures was studied under different temperatures. Both direct and indirect recombination of PL were observed in Ge/Si0.15Ge0.85 MQW and the competitive radiative recombination between direct and indirect recombination were discussed. For temperature dependent PL measurement above room temperature (RT), the relative intensity of direct to indirect recombination markedly increases with the increase of temperature. The enhancement of PL from direct recombination above RT has been attributed to the thermal excitation of carriers from L-type to Γ-type confined states. In addition, the possible transitions of MQW structures were observed in PR measurement above RT. The energy shift coefficient of Ge QW observed in PR was similar with that in PL. And, the energy splitting of light hole (LH) and heavy hole (HH) influenced by strain in MQW was also investigated.