The main difference between a flat-top beam and a Gaussian beam is the intensity distribution of the beam and the application scenarios:
1. Intensity distribution:
Gaussian beam: has a bell-shaped intensity distribution, with the highest intensity in the center and gradually decreasing toward the sides, following a Gaussian distribution curve. This beam has a higher energy density in the center area, but lower energy in the edge area, resulting in uneven energy distribution.
Flat-top beam: has a more uniform intensity distribution across the entire beam cross section, with a relatively constant intensity in the center area and then abruptly dropping toward the edge, forming a flat or plateau-like shape, without the "wings" (low-intensity areas) in a Gaussian beam.
2. Application scenarios:
Gaussian beam: Due to its natural output characteristics, Gaussian beams are often used in applications that require energy to be concentrated to a small area, such as laser cutting, laser welding, and laser marking.
Flat-top beam: suitable for applications that require uniform energy distribution across the entire beam cross section, such as semiconductor wafer processing, material processing, and nonlinear frequency conversion applications, where flat-top beams can provide more accurate and predictable results.
3. Energy efficiency:
Gaussian beam: Due to the presence of low-intensity "wings", Gaussian beams have low energy efficiency and may cause damage to surrounding areas outside the target area.
Flat-top beam: The energy distribution is more uniform and there are no "wings", so the energy utilization efficiency is higher and the damage to the surrounding area is less.
4. Beam shaping:
Gaussian beam: Usually the laser emits a Gaussian beam, which does not require additional beam shaping.
Flat-top beam: The Gaussian beam needs to be shaped by optical elements (such as aspheric lenses, diffractive optical devices, etc.) to obtain a flat-top beam.
5. Cost and complexity:
Gaussian beam: Cost-effective and simple system.
Flat-top beam: Due to the need for additional beam shaping components, the cost and complexity of the system may increase.
6. Beam propagation characteristics:
Gaussian beam: When propagating in free space, the beam profile is still Gaussian even if the beam size changes.
Flat-top beam: When propagating in free space, the intensity shape will change, which is not conducive to long-distance propagation.
In general, flat-top beams and Gaussian beams each have their own advantages, and the choice of which beam to use depends on specific application requirements and cost considerations.
