Reduced quantum defect in a Yb-doped fiber laser by balanced dual-wavelength excitation

Nanjie Yu, Kavita V. Desai, Andrey E. Mironov, Mingye Xiong, Maxime Cavillon, Thomas Hawkins, John Ballato, J. Gary Eden, Peter D. Dragic

Research output: Contribution to journalArticlepeer-review


Two color optical pumping, both above (anti-Stokes pump or ASP) and below (Stokes pump) the lasing wavelength, was adopted to reduce the net quantum defect (QD) in a solid-state Yb-doped fiber laser. The reduction in QD was achieved by converting a substantial portion of the gain medium's phonons directly into useful photons through a dual-wavelength excitation (DWE) mechanism. Since this is achieved through the usual processes of absorption and stimulated emission associated with lasing, high efficiency can be maintained. Both time domain and power measurements are presented, demonstrating a 13.2% reduction of the system's net QD and a 13.8% reduction in the lasing threshold power. These values were limited only by the available ASP power. Laser slope efficiency, with respect to launched ASP power, was found to be as high as 38.3%. A finite difference time domain model, developed to elucidate the role of both pumps in populating the upper states, corroborated the experimental findings. The DWE concept proposed here opens the door to an “excitation-balanced” type of self-cooled fiber laser. Simulation results also suggest that the technique is scalable and conceptually applicable to other solid-state laser systems.

Original languageEnglish (US)
Article number141105
JournalApplied Physics Letters
Issue number14
StatePublished - Oct 4 2021

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'Reduced quantum defect in a Yb-doped fiber laser by balanced dual-wavelength excitation'. Together they form a unique fingerprint.

Cite this