Research on Rare-Earth-Doped Fiber Lasers

Dear Colleagues,

Since the first demonstration of laser operation in a nyeodium-doped phosphate fiber by Koester and Snitzer in 1964, tremendous developments in all aspects of laser performance have been achieved with rare-earth-doped optic fibers over the past six decades. Compared to other laser platforms, fiber lasers have the advantages of outstanding heat-dissipating capability, excellent beam quality, high optical conversion efficiency and high single-pass gain. Relying on the transitions between different energy levels of trivalent rare-earth ions, fiber lasers are able to produce lasers at wavelengths ranging from ultraviolet to visible/near-infrared, and even to mid-infrared. The output power levels of fiber lasers have also undergone tremendous scaling after double-clad rare-earth-doped fibers were invented. A kW-level continuous-wave output can now be easily obtained with a ytterbium-doped double-clad silica fiber. Additionally, pulsed fiber lasers employing different pulse generation techniques have also been developed and ultrashort pulses (shorter than 10 femtoseconds) have been achieved. Nevertheless, rare-earth-doped fiber lasers face many challenges for novel applications.

This Special Issue invites manuscripts that introduce the recent advances in rare-earth-doped fiber lasers. All theoretical, numerical and experimental papers are accepted. Topics include, but are not limited to, the following:

• Novel rare-earth-doped fiber lasers;
• Advanced kW-class fiber laser design and development;
• New power scaling techniques;
• Visible fiber lasers;
• Mid-IR fiber lasers;
• Single-frequency fiber lasers;
• Pulsed fiber lasers;
• Fiber-laser-pumped nonlinear conversion lasers;
• Multi-core and multimode fiber lasers;
• New rare-earth-doped fiber fabrication techniques.

Prof. Dr. Nasser Peyghambarian
Prof. Dr. Xiushan Zhu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Photonics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• fiber lasers
• rare-earth-doped fibers
• continuous-wave fiber lasers
• pulsed fiber lasers
• mode-locked fiber lasers
• visible fiber lasers
• upconversion fiber lasers
• mid-infrared fiber lasers
• fiber-laser-pumped nonlinear conversion lasers
• single-frequency fiber lasers
• multicore fiber lasers
• phosphate fiber lasers
• germanate fiber lasers
• fluoride fiber lasers
• chalcogenide fiber lasers

Title: Experimental study on transverse mode instability of all-fiber single-frequency amplifier based on tapered Yb-doped fiber
Authors: Yue Tao; Zhengfei Mo; Pengrui Kang; Man Jiang; Can Li; Pengfei Ma; Jinyong Leng; Pu Zhou; Zongfu Jiang
Affiliation: 1. College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China 2. Nanhu Laser Laboratory, National University of Defense Technology, Changsha 410073, China 3. Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha 410073, China
Abstract: We experimentally studied the transverse mode instability (TMI) characteristics of a line arly-polarized single-frequency fiber laser amplifier by employing tapered ytterbium-doped fiber (TYDF) under different bending diameters. The TMI threshold is raised from 333 W to 451 W by reducing the bending diameter from 16 cm to 12 cm, accompanied by the deterioration of beam quality from 1.47 to 1.67. The anomaly characteristic between the TMI threshold, bending diameter and the beam quality is mainly due to a decreasing of the bending loss of higher order modes (HOMs) content, as a result of the increased system heat loads caused by tightly bending induced loss of amplification efficiency. It is believed that the presented results will provide useful guide lines for the design and power scaling of high-power single-frequency fiber amplifiers.