2.05 µm holmium-doped all-fiber laser diode-pumped at 1.125 µm. (6th July 2017)

• Record Type: Journal Article
• Authors: Kir'yanov, A V; Barmenkov, Y O; Villegas Garcia, I
• Is Part Of: Laser physics. Volume 27:Number 8(2017:Aug.)
• Publication Date: 2017-07-06
• Subjects: holmium-doped fiber laser -- all-fiber configuration -- continuous-wave operation; Lasers -- Periodicals; 621.36605
• DOI: 10.1088/1555-6611/aa7378
• Languages: English
• ISSNs: 1054-660X

Abstract

Abstract: We report a holmium-doped all-fiber laser oscillating at ~2.05 µ m in continuous wave at direct in-core pumping by a 1.125 µ m laser diode. Two types of home-made holmium-doped alumino-germano-silicate fiber (HDF), differentiated in the Ho 3+ doping level, were fabricated to implement the laser, for revealing the effect of Ho 3+ concentration upon the laser output. Firstly, the fibers were characterized thoroughly from the material and optical viewpoints. Then, laser action with both HDFs was assessed using the simplest Fabry–Perot cavity, assembled by a couple of spectrally adjusted fiber Bragg gratings, also made-in-house. In the best case, when using the lower-doped HDF of proper length (1.4 m), low threshold (~370 mW) and moderate slope efficiency (~13%) of ~2.05 µ m lasing were obtained at 1.125 µ m diode pumping. Long-term stability, high brightness, low noise, and purely CW operation are shown to be the laser's attractive features. Yet, when utilizing the heavier-doped HDF, laser output is revealed to be overall worse, with a possible reason being the deteriorating Ho 3+ concentration-related effects.