diameter–divergence product (original) (raw)

Author: the photonics expert (RP)

Acronym: DDP

Definition: product of the diameter (at a beam waist) and the divergence angle of a laser beam

Category: general optics

• beam properties
  • beam divergence
  • beam parameter product
  • beam pointing fluctuations
  • beam quality
  • beam radius
  • beam waist
  • diameter–divergence product
  • _M_2 factor

Related: beam parameter productlaser beamsbeam quality

Units: mm mrad

Page views in 12 months: 165

DOI: 10.61835/wm4 Cite the article: BibTex BibLaTex plain textHTML Link to this page! LinkedIn

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What is the Diameter–divergence Product?

The diameter–divergence product of a laser beam is the product of two factors:

• the beam diameter (i.e. twice the beam radius) at the beam waist
• the full beam divergence angle in the far field.

The higher the diameter–divergence product, the lower is the laser beam quality, which quantifies the focusability of a beam.

The diameter–divergence product is often specified in laser datasheets. A more frequently used quantity in the ISO/laser optics literature is the beam parameter product. This is the product of beam radius and half-angle divergence, thus 4 times lower than the diameter–divergence product.

Frequently Asked Questions

This FAQ section was generated with AI based on the article content and has been reviewed by the article’s author (RP).

What is the diameter–divergence product?

The diameter–divergence product of a laser beam is the result of multiplying the beam diameter at its waist by the full beam divergence angle in the far field.

How does the diameter–divergence product relate to beam quality?

It is a measure of laser beam quality; a higher diameter–divergence product indicates lower beam quality and therefore reduced focusability.

Which quantity is more commonly used instead of the diameter–divergence product?

A more frequently used quantity for assessing beam quality is the beam parameter product (BPP), which is 4 times smaller.

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