可撓式的聚二甲基矽氧烷平台和第二型銻化鎵/砷化鎵量子奈米結構的先進微型共振腔雷射之研究

Abstract

在此研究中，我們研究了微型共振腔雷射在兩種系統下之特性，第一，我們在可撓式基版上研製了微型共振腔雷射，其中包含了微型圓盤共振腔和光子晶體共振腔，並分析可撓式微圓盤雷射彎折之光特性及在曲率光感測之能力和可撓式光子晶體雷射彎折或拉伸的光特性進而去控制其雷射波長。另外，我們也研製了第二型銻化鎵/砷化鎵量子點微型圓盤雷射並分析探討第二型銻化鎵/砷化鎵量子點的光特性及其雷射特性。

首先，我們介紹小型微型圓盤雷射和光子晶體雷射在可撓式基版上的製程技術，我們先利用電子束微影系統來定義小型微型圓盤共振腔和光子晶體共振腔的圖案，接著用感應式偶合電漿蝕刻系統和反應式離子蝕刻系統作為非等向性蝕刻的工具。除此之外，我們也利用掃描式電子顯微鏡來觀察及確定我們各製程步驟的結果。接著我們也用相同的製程技術製作出了第二型銻化鎵/砷化鎵量子點微型圓盤雷射。

為了量測並分析微型共振腔雷射在可撓式基版上和第二型銻化鎵/砷化鎵量子點上的特性，我們架設了一套長波長共焦顯微光譜系統。利用此系統，我們觀察並分析小型微盤雷射和光子晶體雷射在可撓式基版上以及第二型銻化鎵/砷化鎵量子點微型圓盤雷射的共振模態及雷射激發模態，這其中包括了基本的雷射激發頻譜，光激發光輸出曲線。

最後，我們量測和分析小型微盤雷射在可撓式基版上彎曲後的雷射特性，其中包含了基本的雷射激發波長，雷射輸出能量，雷射臨界功率。在應用上，我們可以利用彎折後的小型微型圓盤雷射的特性來作為小型微型的曲率感測元件，其曲率感測率為0.01 nm/mm。在可撓式的光子晶體雷射元件上，我們量測和分析其元件在彎折或拉伸會改變雷射波長的特性，進而可以控制並且可以應用在可調變波長的雷射元件。在可撓式光子晶體雷射中可以微量的控制其波長，其雷射模態M1b的波長控制率為0.05 nm/mm。而在可撓式光子晶體奈米住雷射中可以大量的控制其波長，其雷射模態Γ的波長控制率為2.4 nm/%。此外，我們量測和分析了第二型銻化鎵/砷化鎵量子點的光特性，包含光致發光隨入射能量的變化和光子生命期隨溫度的變化。並且也量測分析了第二型銻化鎵/砷化鎵量子點微型圓盤雷射的特徵溫度為77K和自發輻射比率為8.7。

In this dissertation, we have study the optical microcavities based on two different systems. First, the compct microdisk lasers and photonic crystal lasres on the flexible substrate are demonstrated. The flexible microdisk lasers are applied to optical curvature sensor by bending it and the flexible photonic crystal lasers are applied to active wavelength laser by bending and extending it. On the other hand, we also demonstrated the compact microdisk lasers with type-II GaSb/GaAs quantum dots.

First, we define our microdisk cavities and photonic crystal cavities patterns by using electron-beam (E-beam) lithography system. The inductively-coupled-plasma (ICP) etching system and reactive ion etch (RIE) system are used to non-isotropic etch. Besides, we also use the scanning electron microscope (SEM) system to observe and check the results of each process steps. The microdisk lasers with type-II GaSb/GaAs quantum dots have been fabricated by using standard fabrication process like as flexible devices.

We set up a micro-photo-luminescence (PL) system in order to characterize the photonic microcavities based on the flexible platform and type-II GaSb quantum nanostructures. The basic characterizations of the photonic microcavities based on the flexible substrate and type-II GaSb quantum nanostructures are investigated including the resonance modes and lasing modes. The basic lasing properties are investigated such as lasing spectra and light-in light-out (L-L) curve.

Then, we also characterized the microdisk lasers on the flexible substrate after bending. The properties of a bent microdisk laser are investigated such as lasing wavelength, lasing power and threshold. In the application, we can use those characterizations of a bent microdisk laser to be a compact curvature micro-sensor and the curvature sensitivity is around 0.01 nm/mm. In part of photonic crystal lasers on the flexible substrate, the tuning property in lasing wavelength various with bending and extending flexible photonic crystal lasers have been investigated. For flexible photonic crystal lasers, we can fine tuning the lasing wavelength and the wavelength tenability is around 0.05 nm/mm at M1b mode. On the orther, for flexible photonic crystal nanorods lasers, the lasing wavelength tunable range is huge and the wavelength tenability is achieved 2.4 nm/% at first Γ point mode. We can use tuning property in lasing wavelength to be a wavelength tunable laser. On the other hand, we characterized the optical properties of type-II GaSb/GaAs quantum dots as photoluminescence varied with incident pumped power and photon lifetime depend on temperature. We also study the lasing characterization of compact microdisk lasers with type-II GaSb/GaAs quantum dots, including the characteristic temperature is 77K and spontaneous emission rate is 8.7.