研究各種產生1.0-3.0微米的雷射光源

Abstract

本論文是利用光激發式半導體雷射、閃光燈式激發摻釹釔鋁石榴石(Nd:YAG)與摻鉺釔鋁石榴石雷射(Er:YAG)以及摻銩(Tm-doped)的雷射來研究在各波長雷射輸出的特性。首先，我們透過改變腔內鑽石散熱片的鍍膜來達到不同雷射共振腔設計需求，實驗結果顯示將鑽石散熱片的鍍膜設計符合雷射激發光與輸出光的波段，將可形成穩定且微小的雷射共振腔並輸出波長在1.52 um的雷射。閃光燈式激發被動式Q開關摻釹釔鋁石榴石雷射可用於誘發空氣爆破實驗，透過變換共振腔內前鏡與輸出耦合鏡不同之曲率半徑組合，可找到最佳的搭配使雷射能量輸出和空氣爆破之能量優化，亦可利用此雷射做腔外光參數震盪之非線性轉換研究，將1.06 um的雷射輸出轉換為1.57 um的波段。在摻鉺釔鋁石榴石雷射的實驗中則利用水冷式的腔體架構做為設計讓功率有效提升，在50 Hz以下的操作頻率下亦可運作如常，輸出對水有良好吸收的2.94 um雷射。而使用摻銩正鋁酸釔(Tm:YAP)雷射在1.94 um可有效達到3 W的雷射輸出。

This thesis presents several optical experiments to explore the laser sources in various lasing wavelength by utilizing optically-pumped eye-safe AlGaInAs laser, flash-pumped passively Q-switched Nd:YAG laser, nonlinear KTP crystal for optical parameter oscillator process, and diode-pumped solid-state Tm-doped and Er-doped lasers. First of all, we demonstrate a linear plane-parallel cavity to investigate the role of dielectic CVD diamond heat spreader is flexible in cavity design. Furthermore, we develop a practical approach to achieve the stack cavity in the length of 2 mm for the concept of microchip laser. The different radius of curvature for cavity mirrors formed a convex-concave cavity to be a flash-pumped passively Q-switched Nd:YAG laser and to investigate the influence on air breakdown energy. The average output energy and the average air breakdown energy decreased gradually while the radius of curvature for output coupler increased from 600 mm to 800 mm. The KTP crystal made a conversion on laser output wavelength from 1.06 um to 1.57 um through the flash-pumped Nd:YAG laser. The solid-state mid-infrared lasers are examined through the Er-doped and Tm-doped crystal. The Er:YAG 2940 nm laser operated on high doping concentration (>30%) to achieve high output energy pumped by flash lamp on quasi continuous-wave mode. The laser output performance of Tm:YAP laser is up to 3.0 W and at the wavelength of 1.94 um. The further investigation of this laser resonator would be briefly discussed in the content.