---
title: "SFG / DFG Wavelengths calculator — AperiOptic"
description: "Sum- and difference-frequency wavelengths for two input photons. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/sfg-dfg-wavelengths"
---

# SFG / DFG Wavelengths calculator

Sum- and difference-frequency wavelengths for two input photons.

Category: [Nonlinear Optics](https://aperioptic.com/calculators)

Formula: `1/λsfg = 1/λ1+1/λ2 · 1/λdfg = |1/λ1−1/λ2|`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| λ1 | `l1` | nm | 800 |
| λ2 | `l2` | nm | 1064 |

## Result with the default inputs

- SFG: 456.6524 nm
- DFG: 3224.2424 nm

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/sfg-dfg-wavelengths?l1=800`](https://aperioptic.com/calculators/sfg-dfg-wavelengths?l1=800). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Sum-frequency generation](https://en.wikipedia.org/wiki/Sum-frequency_generation)

[All optics calculators](https://aperioptic.com/calculators)

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The interactive page: https://aperioptic.com/calculators/sfg-dfg-wavelengths (AperiOptic runs in the browser; free, no account). Every page of the site as Markdown: https://aperioptic.com/llms.txt