Single-mode all glass delivery fiber for ultra-high-power laser system
Zhelezova, Iuliia (2020)
Diplomityö
2020
School of Engineering Science, Laskennallinen tekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2020052839512
https://urn.fi/URN:NBN:fi-fe2020052839512
Tiivistelmä
This work is devoted to investigation of a novel large-mode area (LMA) optical fiber developed for delivery of ultra-short highly intense pulses over several meters’ length. This subject is a bottleneck of the current ultra-short pulsed high-power laser systems and represent important constituent for future progress of industrial lasers and laser-driven applications. The novel optical fiber has a complex all-glass W-type structure ensured fundamental mode confinement and low loss propagation. For the experimental investigation six samples of the delivery fiber with the different geometry has been fabricated and investigated.
This thesis describes the characterization of the main fiber parameters such as sensitivity to the bending, mode field diameter, divergence and beam quality. It includes the details of the experimental setup and the measurement results. The optical launch system has been calculated and realized based on laboratory available lenses.
The investigation revealed a strong fundamental mode confinement in the fiber core resulted in low bending sensitivity and high beam quality up to 15 m length of the fiber. The maximum coupling efficiency was as high as 50 % leaving a small room for further possible improvement.
This thesis describes the characterization of the main fiber parameters such as sensitivity to the bending, mode field diameter, divergence and beam quality. It includes the details of the experimental setup and the measurement results. The optical launch system has been calculated and realized based on laboratory available lenses.
The investigation revealed a strong fundamental mode confinement in the fiber core resulted in low bending sensitivity and high beam quality up to 15 m length of the fiber. The maximum coupling efficiency was as high as 50 % leaving a small room for further possible improvement.