RF-Resolved RIN Engineering of High-Power CW Yb Fiber Laser Architectures Using Seed Topology, Seed Power, Pumping Geometry and Cavity FSR
Abstract
We report, to the best of our knowledge, the first controlled, like-for-like experimental mapping of how four practical design parameters--seed-cavity topology, seed power, amplifier pumping geometry, and seed-cavity free spectral range (FSR)--jointly shape the radio-frequency (RF)-resolved relative intensity noise (RIN) of high-power continuous-wave (CW) Yb-doped fiber lasers. We compare a standalone bidirectional fiber Bragg grating (FBG) oscillator, an FBG-seeded master-oscillator power amplifier (MOPA), and unidirectional ring-seeded MOPAs with FSRs of approximately 11.5 and 5 MHz, all near 1064 nm at a common 72 W output, with RIN measured from 10 kHz to 1 GHz. Across all settings, the low-frequency RIN is technical-noise limited and nearly architecture-independent, whereas RIN above 160 kHz is governed by the seed-cavity topology and its transfer through the amplifier. Higher seed power suppresses the mid- and high-frequency RIN, but the seed-alone and amplified-output comparison reveals opposite transfer for the two topologies: for FBG seeding the 2 MHz-1 GHz RMS RIN increases through amplification (3.66 percent to 4.14 percent at 15 W seed), whereas for ring seeding it decreases (1.47 percent to 1.35 percent). Forward pumping gives the best power-scaling/noise trade-off, while reducing the ring FSR from approximately 11.5 to 5 MHz preserves the high-frequency RIN advantage, confirming it is not a mode-spacing effect. At matched conditions, ring seeding lowers the integrated RMS RIN by 2-3 times (160 kHz-2 MHz) and approximately 3 times (2 MHz-1 GHz, approximately 9-10 dB to near -127.4 dBc/Hz). These results yield band-resolved design rules linking each band to its dominant lever. The unidirectional ring-seeded MOPA thus offers a simple, scalable route to broadband pump-RIN suppression for nonlinear and frequency-conversion photonics.
Related
- Time-resolved topology of aperiodically driven systems
- Beyond Crease Geometry: Multistability in Origami-Inspired Structures through Local Fold Architectures
- Geometry-optimized hyperbolic codes for modular fault-tolerant quantum architectures
- Turning Number and the Geometry of Disorder-Induced Topology
- Spacetime topology and geometry in JT Gravity from non-crossing permutations
BibTeX
@misc{augustine2026rfresolved,
title = {{RF-Resolved RIN Engineering of High-Power CW Yb Fiber Laser Architectures Using Seed Topology, Seed Power, Pumping Geometry and Cavity FSR}},
author = {Anitta Augustine and V. Meher and Shantanu Dambare and V. Balaswamy},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.11856},
eprint = {2610.11856},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.11856},
}
RIS
TY - UNPB
TI - RF-Resolved RIN Engineering of High-Power CW Yb Fiber Laser Architectures Using Seed Topology, Seed Power, Pumping Geometry and Cavity FSR
AU - Anitta Augustine
AU - V. Meher
AU - Shantanu Dambare
AU - V. Balaswamy
PY - 2026
DA - 2026/10/08
PB - arXiv
DO - 10.48550/arxiv.2610.11856
UR - https://arxiv.org/abs/2610.11856
AB - We report, to the best of our knowledge, the first controlled, like-for-like experimental mapping of how four practical design parameters--seed-cavity topology, seed power, amplifier pumping geometry, and seed-cavity free spectral range (FSR)--jointly shape the radio-frequency (RF)-resolved relative intensity noise (RIN) of high-power continuous-wave (CW) Yb-doped fiber lasers. We compare a standalone bidirectional fiber Bragg grating (FBG) oscillator, an FBG-seeded master-oscillator power amplifier (MOPA), and unidirectional ring-seeded MOPAs with FSRs of approximately 11.5 and 5 MHz, all near 1064 nm at a common 72 W output, with RIN measured from 10 kHz to 1 GHz. Across all settings, the low-frequency RIN is technical-noise limited and nearly architecture-independent, whereas RIN above 160 kHz is governed by the seed-cavity topology and its transfer through the amplifier. Higher seed power suppresses the mid- and high-frequency RIN, but the seed-alone and amplified-output comparison reveals opposite transfer for the two topologies: for FBG seeding the 2 MHz-1 GHz RMS RIN increases through amplification (3.66 percent to 4.14 percent at 15 W seed), whereas for ring seeding it decreases (1.47 percent to 1.35 percent). Forward pumping gives the best power-scaling/noise trade-off, while reducing the ring FSR from approximately 11.5 to 5 MHz preserves the high-frequency RIN advantage, confirming it is not a mode-spacing effect. At matched conditions, ring seeding lowers the integrated RMS RIN by 2-3 times (160 kHz-2 MHz) and approximately 3 times (2 MHz-1 GHz, approximately 9-10 dB to near -127.4 dBc/Hz). These results yield band-resolved design rules linking each band to its dominant lever. The unidirectional ring-seeded MOPA thus offers a simple, scalable route to broadband pump-RIN suppression for nonlinear and frequency-conversion photonics.
ER -