在本論文中，會探討940nm波段之垂直共振腔面射型雷射(VCSEL)的陣列製程設計及操作，與傳統的VCSEL陣列結構不同，我們將陣列中的各個Mesa以波導的形式互相連結，此外也透過鋅擴散與氧化掏離的技術來套用在傳統以及有波導的VCSEL陣列結構中，可以實現具有高亮度(單模態)的輸出以及能有效降低元件面積增加所造成的RC頻寬劣化。 與傳統無波導的陣列相比，證明了有波導的陣列有更高的Wall plug效率、更大的輸出功率以及更好的眼圖品質，能夠顯著的改善資料傳輸，並且保持狹窄的發散角(半高寬FWHM：～6o)，我們所製作出的3×3 VCSEL陣列元件可達到在110mA時功率為50mW，發散角之半高寬(FWHM)為8o，在Data rate為10 Gbit/s時有清晰的眼圖傳輸以及頻寬能夠達到10GHz。 VCSEL在單模操作下，通常會有電洞燒盡(spatial hole burning)效應，這是導致單模態VCSEL陣列靜態與動態特性的主要瓶頸，而我們所設計之光波導VCSEL陣列的優異特性可歸因於在陣列中每顆VCSEL的單模態輸出模式中，高光子密度透過孔徑與孔徑之間的波導連接所稀釋而使得特性可提升。而這種新穎的有波導之高速、高亮度940nm波段VCSEL陣列具有強大的潛力，可以更為有效地應用於光無線通訊系統中。 ;A novel structure of VCSEL array for high-efficiency, high-speed, and high brightness performances have been demonstrated. In contrast to the traditional VCSEL arrays, which have several independent VCSEL cavities in parallel, here the array structure we demonstrate has additional passive optical waveguides to connect each cavity. In addition, the Zn-diffusion and oxide-relief structures are adopted in each single element in the array to have high-brightness (single mode) output and relax its RC-limited bandwidth. As compared to the single mode (SM) reference without waveguide connections in the array, the demonstrated array can have significant improvements in terms of higher wall plug efficiency (WPE), larger maximum output power, better quality of eye opening for high-speed data transmission, and keep at the same narrow divergence angle (full-width half-maximum: ~6o). Our VCSEL device can achieve output power 50mW, divergence angle (FWHM) 8o at 110mA. We can get clear eye pattern at 10Gbit/s data rate and E-O bandwidth achieve 10GHz in 3×3 array. These superior performances of demonstrated array can be attributed to that the high photon density in the SM output pattern from each VCSEL unit is diluted through the connected passive waveguides between different apertures. The reduction in photon density for SM operation can thus release the spatial hole burning effect, which is usually the major bottleneck for static and dynamic performances of SM VCSEL array. This novel high-speed and high-brightness 940 nm VCSEL has strong potential to serve as a light source in free-space optical communication.
