The M2 parameter in space ---beam quality factor Chengao Wang

Review of the fundamental Gaussian modes in laser beams Amplitude distribution at beam waist Amplitude distribution at any position

Review of the fundamental Gaussian modes in laser beams Rayleigh Range Propagation of the beam

Review of the fundamental Gaussian modes in laser beams In the far field, Divergence angle:

Review of the fundamental Gaussian modes in laser beams Rewrite the propagation of the beam using the definition of the divergence angle:

The interpretation for “beam quality” How the beam diverges in the far-field and how it focuses in the near-field

Uncertainty Relationship

Uncertainty relationship in Gaussian beams

Uncertainty relationship in Gaussian beams By Fourier transformation

Uncertainty relationship in Gaussian beams

Definition of the parameters in real laser beams spot size Divergence angle

The definition of M M is named as times diffraction limit number, which characterize the beam quality for a real laser beam

Propagation function for a real laser beam For Gaussian beam For real laser beams

Introduction to the instrument

Applications Quality control Process control Product or process development

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