Rayleigh range and the m(2) factor for bessel-gauss beams.

Area of Science:

• Optics
• Beam Propagation

Background:

• Bessel-Gauss beams offer unique propagation characteristics.
• The M(2) factor quantifies beam quality and divergence.
• Accurate prediction of beam propagation parameters is crucial for applications.

Purpose of the Study:

• To analyze the predictive accuracy of the M(2) factor for Bessel-Gauss beams.
• To compare the axial intensity positions predicted by the M(2) factor with actual beam behavior.
• To investigate the relationship between Bessel-Gauss and Gaussian beams regarding intensity profiles and lengths.

Main Methods:

• Theoretical analysis of the M(2) factor for Bessel-Gauss beams.
• Comparison of predicted axial positions (e(-2) and half-intensity) with beam propagation models.
• Calculation of intensity ratios and products for Bessel-Gauss and Gaussian beams.

Main Results:

• The M(2) factor predicts the e(-2) axial position for large k(t)w(0) values.
• For small k(t)w(0), the M(2) factor predicts the half-intensity axial position for J(0) Bessel-Gauss beams.
• The ratio of half-intensity lengths is M(2)/1.3, and peak intensity-range product is 1.3x higher for Bessel-Gauss beams.

Conclusions:

• The M(2) factor's predictive capability for Bessel-Gauss beam axial positions is parameter-dependent.
• Bessel-Gauss beams exhibit enhanced intensity-range products compared to Gaussian beams.
• These findings refine the understanding of Bessel-Gauss beam propagation and quality assessment.