有機薄膜化二維分佈回饋型雷射之發光特性研究

Emission Characteristics of Organic Thin-film Lasers with Two-dimensional Distributed Feedback

張麗雯(Li-Wen Chang)

指導教授 ： 楊士禮

國立清華大學/電機資訊學院/光電科技產業研發碩士專班/碩士(2007年)

https://doi.org/10.6843/NTHU.2007.00490

摘要

本篇論文主要探討有機雷射的發光特性及設計原理。我們選用發紅光的有機小分子材料4-(dicyanomethy-lene)-2-terbuty1-6-(1,1,7,7-tetramethyljulolidin-4-y1-vinyl)- 4H-pyrn (DCJTB) 做為雷射的增益介質，並且將其摻雜在不同分子量的高分子材料Poly(N-vinylcarbazole) (PVK)中以增加發光特性。我們利用自發性激發放大（Amplified spontaneous emission） 的理論定義出DCJTB在不同的光激發能量下，其增益係數與損耗係數的變化，以找出最合適的PVK摻雜分子量。雷射的共振腔設計則採用二維的反覆回饋式（distributed feedback）結構，並且利用電子束微影術（electron beam lithography）的製程完成結構製作，最後將有機溶液旋轉塗布上此二維的反覆回饋式結構便完成有機雷射的製作程序。透過外部激發光源的驅動，我們成功的觀測到雷射放光的現象，其發光波長為621奈米，在論文的最後也探討了雷射出光的遠場發光圖形。

關鍵字

有機雷射 ； 自發性激發放大 ； 增益係數 ； 損耗係數 ； 反覆回饋式

並列摘要

This thesis is concentrated on the emission behaviors of an optically pumped composite organic thin-film laser with two-dimensional distributed feedback (2D-DFB) structure. We use famous red fluorescent dye of 4-(dicyanomethy-lene)-2-terbuty1-6-(1,1,7,7-
tetramethyljulolidin-4-y1-vinyl)-4H-pyran (DCJTB) as the laser gain media which reveals strongly amplified spontaneous emission (ASE) phenomenon. We report the optical gain and loss characteristics of DCJTB doped in Poly(N-vinylcarbazole) (PVK) of different molecular weight, 90000 and 1100000, respectively via ASE theory. 2D-DFB structure with triangular lattice is adopted for laser cavity and fabricates by electron beam lithography. With a suitable laser cavity and the high gain material, lasing action with peak wavelength of 621 nm is observed in the organic 2D-DFB laser. The far-field emission pattern is also discussion in this thesis.

並列關鍵字

organic thin-film laser ； two-dimensional distributed feedback ； triangular lattice ； DCJTB ； amplified spontaneous emission

參考文獻

1. A. J. Heeger, “Semiconducting and Metallic Polymers: The Fourth Generation of Polymeric Materials--Nobel Lecture,” J. Phys. Chem. B, 105, pp. 8475 (2001).

2. K. Kobayashi, W. J. Blau, H. Tillman and H.-H. Hörhold, “Light Amplified and Lasing in a Stilbenoid Compound-Doped Glass-Clad Polymer Optical Fiber,” IEEE J. Quantum Electronics, 39, pp. 664-672 (2003).

3. D. W. Samuel and Graham A. Turnbull, “Polymer Lasers: Recent Advances,” Material today, 7, pp. 28-35 (2004).

4. P. P. Sorokin and J. R. Lankard, “Stimulated Emission Observed from an Organic Dye, Chloro-aluminum Phthalocyanine,” IBM J. Res. Develop. 10, pp. 162-163 (1966).

5. H. Kogelnik and C. V. Shank,” Stimulated Emission in a Periodic Structure,” Appl. Phys. Lett., 18, pp. 152-154 (1971).