TY - JOUR

T1 - Stationary High-Energy Pulse Generation in Er-Based Fiber Lasers via Quasi-Synchronous Gain Modulation

AU - Nyushkov, Boris

AU - Ivanenko, Aleksey

AU - Koliada, Natalia

AU - Smirnov, Sergey

N1 - The experimental study and validation of the reported pulse generation method were supported by the Russian Science Foundation (grant 17-72-30006-P). B.N. also acknowledges the support of the Ministry of Science and Higher Education of the Russian Federation (project FSUN-2023-0007) for the analysis of the applicability conditions of the considered pulse-shaping method.

PY - 2024/1

Y1 - 2024/1

N2 - We demonstrate the feasibility of triggering stationary high-energy pulse generation in Er-doped fiber lasers at ~1.5 µm via quasi-synchronous gain modulation. This simple method relies upon the sine-wave modulation of pump power at a frequency slightly surpassing the intrinsic frequency spacing of longitudinal modes in the laser cavity. This was previously implemented only in Yb-doped fiber lasers at ~1.1 µm. Here, for the first time, we experimentally validate the pulse shaping capabilities of this method also in Er fiber lasers, which, unlike Yb fiber lasers, have a three-level laser energy diagram (when pumped at 0.98 µm) with a very long-lived (10 ms) upper laser level. The feasibility of the method was validated both for normal and anomalous intracavity dispersion, which was not available in previous implementations in Yb fiber lasers at ~1.1 µm. Thus, the stable generation of a regular train of discrete nanosecond pulses with an energy of up to 180 nJ was achieved in our test-bed Er fiber laser upon the quasi-synchronous sine-wave modulation of the pump power at 0.98 µm. The results of our study testify to the general applicability of this affordable and reliable method for high-energy pulse generation in various rare-earth-doped fiber lasers.

AB - We demonstrate the feasibility of triggering stationary high-energy pulse generation in Er-doped fiber lasers at ~1.5 µm via quasi-synchronous gain modulation. This simple method relies upon the sine-wave modulation of pump power at a frequency slightly surpassing the intrinsic frequency spacing of longitudinal modes in the laser cavity. This was previously implemented only in Yb-doped fiber lasers at ~1.1 µm. Here, for the first time, we experimentally validate the pulse shaping capabilities of this method also in Er fiber lasers, which, unlike Yb fiber lasers, have a three-level laser energy diagram (when pumped at 0.98 µm) with a very long-lived (10 ms) upper laser level. The feasibility of the method was validated both for normal and anomalous intracavity dispersion, which was not available in previous implementations in Yb fiber lasers at ~1.1 µm. Thus, the stable generation of a regular train of discrete nanosecond pulses with an energy of up to 180 nJ was achieved in our test-bed Er fiber laser upon the quasi-synchronous sine-wave modulation of the pump power at 0.98 µm. The results of our study testify to the general applicability of this affordable and reliable method for high-energy pulse generation in various rare-earth-doped fiber lasers.

KW - fiber laser

KW - intracavity dispersion

KW - pulse energy

KW - pulse shaping

KW - quasi-synchronous gain modulation

KW - rare-earth-doped fibers

KW - stationary pulse generation

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85183345499&origin=inward&txGid=fa73e8fdbc6722d36df6dd8f1676439b

UR - https://www.mendeley.com/catalogue/07fabfc0-1695-3aed-b24d-a9bd2e38369b/

U2 - 10.3390/photonics11010037

DO - 10.3390/photonics11010037

M3 - Article

VL - 11

JO - Photonics

JF - Photonics

SN - 2304-6732

IS - 1

M1 - 37

ER -