腔內被動式Q開關之光學參數振盪器研究

Abstract

利用腔內光學參數振盪器來產生1.5□m左右波長的人眼安全雷射，在14W激發光源下，已可得到1.6ns、10kW的輸出；在我們實驗中，使用Nd:GdVO4當作增益介質可以得到奈米以下(0.7ns)的脈衝寬度，以及20kW的脈衝功率輸出。並可利用two-mirror的架構，使腔內光學參數振盪器更穩定，且提高其脈衝能量約150%；並將穩定的特性運用在可調式波長，可得到0.4nm/0C的調整波長斜率，增加使用的便利性。且使用Nd:Gd0.7Y0.3VO4比Nd:YVO4的脈衝功率約3倍高、比Nd:GdVO4的脈衝功率約1.8倍高。

Extremely short (1.6 ns) high-peak-power (> 10 kW) pulses of lasers at the eye-safe wavelength region about 1.5 □m are obtained by intracavity optical parametric oscillators (OPOs). We demonstrated a compact efficient eye-safe OPO pumped by a diode-pumped passively Q-switched Nd:GdVO4 laser to produce peak powers at 1571 nm higher than 20 kW with pulse widths of 0.7ns . On the other hand, we overcome the instablility in the IOPO by using two-mirror structure .At the same time, we raise the pulse energy to 1.5 times. Due to its stability, we try to apply the two-mirror structure to tune wavelengths by temperature. As a result, we can get the curve slope about 0.4nm/0C. By the way, using Nd:Gd0.7Y0.3VO4 crystals may get 3 times the pulse energy by using Nd:YVO4 crystals and 1.8 times the pulse energy by using Nd:GdVO4 crystals.