About Photonics Calculators
Photonics Calculators is a free, open-source collection of 411interactive tools covering the breadth of optics and photonics — from laser safety and fiber optics to thin-film coatings, wave optics, and free-space communications.
Each calculator recomputes as you type. Its charts are drawn as SVG, or with Plotly.js where a plot needs zoom and hover. The goal is to make common photonics calculations accessible without needing MATLAB, Python, or proprietary software.
Built by a photonics engineer who got tired of reaching for a spreadsheet every time they needed a quick NOHD or ABCD matrix calculation.
Model Tiers
Each calculator page shows how far its model can be trusted, and the references it was checked against.
- Exact (114 pages)
- The equations are exact within the stated assumptions, or are a standard's tabulated values. The results are as good as the inputs.
- Textbook approximation (286 pages)
- A standard approximation from the literature (for example paraxial, plane-wave or Gaussian-beam), valid within the range the page states.
- Illustrative (11 pages)
- A simplified model that shows trends and orders of magnitude. Don't use its numbers for design.
- Not yet reviewed (0 pages)
- This page's model hasn't been checked against published references yet. Cross-check its results before relying on them.
How the Calculators Are Checked
- 411 of 411 pages have a model tier from a physics audit (the counts are above). Each page states what its model assumes or leaves out.
- 1206 automated tests in 182 files check the physics functions, mostly against values from the cited references or an independent hand calculation, plus limits and domain edges. All 1280 tests must pass before any change is merged.
- A blind audit (November 2026) drew 30 tiered pages at random, 3 per category, with a fixed seed (20261106) so anyone can redraw the same pages. Reviewers recomputed every displayed result from the live page, at the default inputs and at a second input set, against the cited references, before reading the code. No page had a wrong result, so the share of pages with a wrong result is below 9.5 % at 95 % confidence (Clopper–Pearson); the audit can't show that it is zero. 7 pages had a minor issue (a label, wording, a rounding gap); all 7 are fixed. Limits: the reviewers were AI models (Claude), the same family that wrote the code, not independent human experts, and 8 pages were checked against the source text, the other 22 against the standard textbook result. Full results and method.
- The pages cite 970 distinct references (1294 citations in all); 819 of them link to a DOI or an open copy.
Checks miss things. If a value, formula or reference looks wrong, every calculator has a “Report a problem” form at the bottom of its page, and the one below takes general reports.
Report a problem
Physics References
The general textbooks and standards behind many pages; each page lists the specific sources it was checked against:
- Saleh, B. E. A. & Teich, M. C. — Fundamentals of Photonics, 3rd Ed. (2023)
- Hecht, E. — Optics, 5th Ed. (2016)
- Born, M. & Wolf, E. — Principles of Optics, 7th Ed. (1999)
- Siegman, A. E. — Lasers (1986)
- Agrawal, G. P. — Fiber-Optic Communication Systems, 5th Ed. (2021)
- MacLeod, H. A. — Thin-Film Optical Filters, 4th Ed. (2010)
- IEC 60825-1 — Safety of laser products
- ANSI Z136.1 — American National Standard for Safe Use of Lasers
⚠️ Disclaimer
These calculators are provided for educational and reference purposes only. While every effort has been made to implement formulas accurately, they should not be used as the sole basis for safety-critical decisions — especially laser safety classifications, optical component specifications, or any calculation where errors could result in personal injury or equipment damage.
Always verify results against official standards (IEC 60825-1, ANSI Z136.1), manufacturer datasheets, and consult a qualified laser safety officer or optical engineer for critical applications.