In optics, a Gaussian beam is an idealized beam of electromagnetic radiation whose amplitude envelope in the transverse plane is given by a Gaussian function; this also implies a Gaussian intensity (irradiance) profile.

The beam waist (or beam focus) of a laser beam is the location along the propagation direction where the beam radius has a minimum. The waist radius is the beam radius at that location. Figure 1: The beam waist is the location where the beam radius is smallest.

Due to diffraction, a Gaussian beam will converge and diverge from an area called the beam waist (w 0), which is where the beam diameter reaches a minimum value. The beam converges and diverges equally on both sides of the beam waist by the divergence angle θ (Figure 2).

This calculator gives you the laser spot size and laser beam waist values based on the beam diameter at lens, wavelength, and other parameters you input.

Terms like “beam size”, “waist size”, “beam width” and alike are suitable only for qualitative statements like “The beam size sharply increases as the resonator length approaches the stability limit”. But nobody knows for sure whether some “size” or …

The plane z =0 marks the location of a Gaussian waist, or a place where the wavefront is flat, and w 0 is called the beam waist radius. The irradiance distribution of the Gaussian TEM 00 beam, namely, where w = w(z) and P is the total power in the beam, is …

Understanding the beam waist is fundamental for designing and optimizing laser systems. By grasping the concepts of beam waist, Rayleigh range, and divergence, and knowing how to calculate and measure these parameters, one can ensure the optimal performance of laser systems in various applications.

Beam Waist. The beam waist is the narrowest point of a Gaussian beam, where the beam diameter is at its minimum. The shape of the beam waist is similar to the narrow point of an hourglass. At the waist, the beam’s intensity distribution is perfectly Gaussian, with a maximum at the center and symmetrical decay outward.

We use the beam half-width, the radial distance (`w`) from the central axis such that `E (w) = E_0/e` (where the electric field is `1/e` of its value at the central axis). The beam waist is the smallest beam half-width for a given beam (where the beam is "skinniest").

In the free space between lenses, mirrors and other optical elements, the position of the beam waist and the waist diameter completely describe the beam. When a beam passes through a lens, mirror, or dielectric interface, the wavefront curvature is changed, resulting in new values of waist position and waist diameter on the output side of the ...