820nm反饋式半導體雷射與單一砷化銦量子點之研究

Abstract

由於光資訊儲存容量日漸增加，伴隨著光學讀取頭的雷射光波段也需愈短的波段來讀取。如傳統影音光碟與數位影音光碟，它們的儲存容量分別為單片單面680MBytes 和 4.7 Gbytes，光學讀取頭則為780nm和650nm波段。如今新一代的高畫質數位多功能光碟已開發出，其儲存容量可高達單片單面15Gbytes，但其讀取頭的波段需使用400-420nm。這在目前的研發技術及成本考量上是有困難的。因此我們在此提出另一種方式: 製造一個高功率的820nm反餽式半導體雷射然後利用二倍頻技術使射出的雷射光波段座落於400~420nm作為高畫質數位多功能光碟的光學讀取頭。在此論文的第一部分，我們成功地製作出在CW的操作模式下可達4nm調變波段以及邊模抑制比為25dB 的820nm反餽式半導體雷射。第二部分我們提出一種選擇性成長單一砷化銦量子點的方式，使成長的量子點能做落在預先設計好的平台上。利用此方法，我們可以輕易的製作出二維度的單一量子點矩陣。

As a result of optical storage capacity is getting larger , the wavelength of optical pickup head is getting shorter .For example :the capacity of Video Compact Disc (VCD) and Digital Video Disc(DVD) are 680MBytes/single side and 4.7GBytes/single side respectively. Their pickup head use 780nm and 650 nm wavelength laser diodes. Now new generation of High-Definition DVD (HD-DVD) is shown, whose capacity is getting up to 15 GBytes/single side and need 400-420 nm wavelength laser source to pickup. But there are some technological and cost problems in developing such shorter wavelength of laser diodes. So we want to fabricate a conventional and powerful 820nm Distributed Feedback (DFB) Laser and emits 400-420nm wavelength by second harmonic generation technique to be a pickup head of HD-DVD. In sectionⅠ, we have successfully fabricated a 820nm DFB laser with tunning range 4nm (CW operation), side mode suppression ratio (SMSR) 25dB . In sectionⅡ,we develop a selective growth to form single quantum dots on predesigned mesas with added strain . Using this technique, we can grow two-dimensional single quantum dots arrays easily.