Variation of structured laser beam pattern and optimization for an alignment reference line creation

Area of Science:

• Optics and Photonics
• Particle Accelerator Technology
• Metrology

Background:

• Accurate alignment of particle accelerators requires a stable, straight reference line over long distances.
• Traditional Gaussian laser beams exhibit significant divergence, limiting their suitability for precise alignment.
• Structured Laser Beams (SLBs) offer a potential solution due to their unique intensity profiles and reduced divergence.

Purpose of the Study:

• To investigate the suitability of Structured Laser Beams (SLBs) as a straight-line reference for long-distance particle accelerator alignment.
• To analyze the relationship between the inner core (IC) and outermost ring (OR) size of SLBs based on generator design parameters.
• To determine optimal SLB parameters for efficient and accurate alignment systems.

Main Methods:

• Numerical simulations were employed to model SLB propagation and intensity profiles.
• Experimental setups were used to generate and analyze SLBs with different configurations over distances up to 50 meters.
• Transversal intensity profiles and wavefronts of various SLBs were measured and compared.

Main Results:

• SLBs demonstrate potential as stable, straight references for long-distance alignment applications.
• The divergence of the SLB's inner core can be limited to approximately 10 microradians.
• A trade-off exists between minimizing the size of the inner core and the outermost ring, influenced by generator design.

Conclusions:

• Structured Laser Beams are generally suitable for long-distance alignment in particle accelerators.
• Careful selection of SLB generator parameters is crucial to balance the size of the inner core and outermost ring.
• Further optimization of SLB parameters can enhance accuracy for specific alignment conditions.