Wiki

A searchable home for the optics notes behind the calculator: formulas, propagation rules, design patterns, and worked laser layout examples.

Gaussian beam equations: from TEM₀₀ field to lens focusing

A connected derivation from field amplitude to intensity, beam radius, Rayleigh range, q parameter, ABCD propagation, and the Gaussian thin-lens transform.

Foundations ABCD Focusing Derivation
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F-number and numerical aperture for Gaussian beams

How the illuminated beam diameter sets effective f-number and NA, why a lens's clear aperture can be misleading, and when the paraxial design rule applies.

F-number NA Focusing
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M² beam quality: meaning and measurement

What M² says about divergence and focusability, how to interpret its value, and how to obtain it from a standards-based beam-caustic measurement.

Beam quality Measurement
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Laser beam expander design: Galilean and Keplerian telescopes

How to choose and space two-lens beam expanders, compare Galilean and Keplerian layouts, and open a worked 852 nm fiber example in the calculator.

Design Telescope Galilean Example
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Choosing the shortest practical Galilean or Keplerian beam expander

A compact design trick: choose the largest acceptable internal ray angle, then calculate focal lengths and spacing for the shortest useful telescope.

Design Compact layouts Galilean Keplerian
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DiffBeam MCP for Gaussian beam optics

How compatible AI clients can use DiffBeam's read-only catalog MCP and capability-bound live workspace bridge without model coupling.

MCP AI clients Contracts Examples
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