Ultra-narrow linewidth Tm3+-doped fiber laser based on intra-core fiber Bragg gratings

• Published in: Laser physics letters 2009-10, Vol.6 (10), p.723-726
• Main Authors: Zhang, Y.J., Wang, W., Song, S.F., Wang, Z.G.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; fiber Bragg grating; Fiber lasers; Fiber optics; Fundamental areas of phenomenology (including applications); Gratings; Lasers; Nonlinear optics; Optical elements, devices, and systems; Optics; Other fiber-optical devices; Physics; ultrafast laser; Ultrafast processes; optical pulse generation and pulse compression
• ISSN: 1612-2011; 1612-202X
• DOI: 10.1002/lapl.200910064

A 74 pm ultra‐narrow linewidth diode laser (LD) claddingding‐pumped Tm3+‐doped fiber laser was reported. The maximal continuous wave (CW) output power was 14.5 W at 1946 nm, with a slope efficiency of 37.5% and the threshold of 5.3 W. The single‐mode double‐cladding Tm3+‐doped fiber had a core diameter of 15 μ m (NA:0.1), and the regular hexagonal inner‐cladding diameter was 200 μ m (NA:0.46). The high reflection coupler was based on the intra‐core fiber Bragg gratings (FBGs), which were directly written into the Tm3+‐doped non‐photosensitive fiber core by the 800 nm femtosecond laser and a phase mask. The output coupler was the other fiber end with 3.6% Fresnel reflection, and the pump source was a high power 792 nm LD with a 200 μ m pigtail fiber output. According to our knowledge, this was the first report on the ultra‐narrow linewidth Tm3+‐doped fiber laser using intra‐core FBGs approximately 2 μ m. (© 2009 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)