A mature 100-W 1178-nm single-frequency linearly-polarized Raman fiber amplifier for laser guide star assisted optical ground station adaptive optics systems
Notice bibliographique
Résumé
While the next generation of satellite constellations provide improved capacity through the use of optical inter-satellite links, there is still a capacity bottleneck at the RF feeder links between satellites and ground stations, which are an order of magnitude slower in moving data. In order to move to all optical feeder links, there is a challenge to overcome the distortion associated with atmospheric turbulence. Laser Guide Star (LGS) adaptive optics systems are a key enabling technology to help solve this beam wander problem for ground to space optical systems. For guide star lasers suitable for daytime LGS operation, high power is key. To respond to this need, a 100-W continuous-wave (CW) 1178-nm narrow-band polarization-maintaining (PM) Raman fiber amplifier (RFA) has been developed and fully engineered. A linearly-polarized single-frequency 1178-nm seed laser with an output power of only a few mW is amplified up to 100 W in a two-stage RFA counter-pumped by a 200-W 1120-nm PM fiber laser. Techniques for efficient suppression of stimulated Brillouin scattering (SBS) have been optimized, resulting in the RFA SBS threshold being pushed beyond the 100-W level. The narrow linewidth of the seed laser is well preserved in the RFA, without any evidence of linewidth broadening up to 100 W. The RFA is based on true single-mode PM fibers and has excellent polarization purity and output beam quality, key factors for subsequent efficient frequency doubling to the Na absorption line at 589 nm in a resonant frequency-doubling cavity. Similar to the widely-deployed MPBC/TOPTICA <i>SodiumStar</i> 20/2, the new 100-W RFA system is a compact, modular, reliable and ruggedized off-the-shelf system ready for integration. Compared to solid-state alternatives, a guide star laser based on an all-fiber, highly-reliable, 100-W RFA not only provides excellent overall wall-plug efficiency due to its high pump-to-Raman optical conversion efficiency, but also maximizes the important “up time” for the optical channel at ground station facilities since it is a maintenance-free and turn-key system. To confirm the stability and reliability of this next-generation guide star RFA, the system was run 24/7 at the full 100 W for a total of 1300 hours. The test results confirmed that the 100-W RFA system is extremely robust and reliable, with a sufficient built-in 1120-nm pump power margin. Re-measurements of key RFA parameters, such as polarization purity and output beam quality, also confirmed that the RFA performance remained unchanged after the 1300-hour 100-W test. Assuming a conservative conversion efficiency of ~ 80% by a resonant frequency doubler and taking into account typical passive coupling losses into the doubler cavity of < 15%, narrow-linewidth CW guide star lasers with powers < 70 W at 589 nm can confidently be expected for future optical ground station adaptive optics systems. The RFA output power was shown to be solely limited by the SBS threshold. Since all the laser components showed sufficient higher optical power handling potential, it is expected that, with further optimization of the SBS suppression, the RFA output power can be scaled significantly beyond the current 100-W level.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».