Goya Kenji, Matsukuma Hiraku, Uehara Hiyori, Hattori Satoshi, Schäfer Christian, Konishi Daisuke, Murakami Masanao, Tokita Shigeki
Opt Express. 2018 Dec 10;26(25):33305-33313. doi: 10.1364/OE.26.033305.
We report the femtosecond laser inscription of fiber Bragg gratings (FBGs) in an Er-doped fluoride glass fiber used for lasing at a mid-infrared wavelength of 2.8 µm. The lasing evolution is discussed in terms of the FBG reflectivity, wavelength transition to the Bragg wavelength, and output power of the mid-infrared fiber laser. A first-order and short (2.5-mm-long) Bragg grating showed a reflectivity of 97%, because of a laser-induced index modulation of 1.1 × 10. This modulation was sufficient to saturate this system's output power. The laser oscillator is designed to lase in the atmospheric window of 2799-2800 nm slope. Further, this oscillator's efficiency is as high as 29.1% for the launched pump power over the range of 0.4-4.6 W and at a lasing wavelength of 2799.7 nm. This oscillator also exhibited a FWHM bandwidth of 0.12 nm.
我们报道了用于 2.8 微米中红外波长激光的掺铒氟化物玻璃光纤中飞秒激光写入光纤布拉格光栅（FBG）的情况。从 FBG 反射率、向布拉格波长的波长跃迁以及中红外光纤激光器的输出功率方面讨论了激光演化情况。一个一阶且短（2.5 毫米长）的布拉格光栅显示出 97%的反射率，这是由于激光诱导的 1.1×10 的折射率调制。这种调制足以使该系统的输出功率饱和。激光振荡器被设计为在 2799 - 2800 纳米斜率的大气窗口中产生激光。此外，对于 0.4 - 4.6 瓦范围内的泵浦功率以及 2799.7 纳米的激光波长，该振荡器的效率高达 29.1%。该振荡器还表现出 0.12 纳米的半高宽带宽。
