`Theta = (2 * lambda )/ (pi * w_0 )`

Enter a value for all fields

The Full-Angular Width calculator computes the full-angular width for a Gaussian Beam (Θ) based on the wavelength (λ) and the beam waist (ω₀).

INSTRUCTIONS: Choose units and enter the following:

• (ω₀) Beam Wais.
• (λ) Wavelength.

Full-angular Width (Θ):  The calculator returns the width in radians.  However, this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The formula for the Full-Angular Width for a Gaussian Beam is:

      Θ = (2·λ)/(π·ω₀)

where:

• Θ is the Full-Angular width for a Gaussian beam
• λ is the wavelength
• ω₀ is the beam waist

This Full-Angular Width equation¹ calculates the full-angular width (Θ) for a Gaussian Beam.  Θ is used as an indicator of how quickly the beam spreads as it travels.  A larger Θ means the beam is spreading more.  For more information on full-angular width and Gaussian Beams in general, please see the Gaussian Beam Calculator.

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Gaussian Beam Calculators

• Rayleigh range 
• Full-angular width (Θ)
• Beam half-width
• Beam Waist

1. ^ Hecht, Eugene. "Modern Optics: Lasers and Other Topics." Optics. Reading, MA: Addison-Wesley, 2002. 618. Print.