Phosphate solid-state photonic crystal fiber developed successfully

Recently, the Shanghai Institute of Optics and Fine Mechanics, Academia Sinica, for the first time, put forward the concept of all-solid-state photonic crystal fiber phosphate and successfully developed. This solution replaces the air holes with low refractive index glass, avoids the defects caused by the presence of air holes and makes the all-fiber laser possible, and the use of soft glass also significantly improves the pump absorption rate and nonlinearity Threshold.

Using a 6wt% ytterbium-doped high-quality phosphate glass, Shanghai Komatsu Co., Ltd. successfully fabricated a single-mode output with a core diameter of 17 micrometers by a combination of tube-sticking and stacking methods. The polarization-maintaining phosphoric acid Salt solid-state photonic crystal fiber, the laser output of 13.8 W is realized in a 40 cm optical fiber, and the polarization maintaining performance of the optical fiber is realized by changing the symmetry of the optical fiber, and the degree of polarization maintaining reaches 80%.

Due to the stable properties of quartz optical fiber, low transmission loss and high softening point, the current research on large mode field optical fiber mainly focuses on quartz optical fiber. However, the low solubility and low threshold of nonlinearity of quartz optical fiber make the pump absorption rate low, meanwhile the nonlinear effect is obvious at high power output, which seriously affects the further output of fiber laser. At present, most of the low refractive index rods constituting the photonic crystal arrangement in the quartz PCF are made of air, which not only makes the preparation and storage of the optical fiber complicated and costly but also lowers the thermal conductivity of the air, When the phenomenon of unstable mode, affecting the stability of the beam quality. At the same time, the existence of air holes makes it difficult to weld with the traditional pigtail output device, including the pump source, resulting in an all-fiber laser.

The all-solid-state photonic crystal fiber developed by Shanghai Institute of Optics and Fine Mechanics proposed a new large-mode field optical fiber structure, which successfully solved the shortcomings of difficult and difficult-to-implement all-fiber laser such as difficult welding, poor heat dissipation and hard fiber.