---
title: "Group Delay Dispersion calculator — AperiOptic"
description: "Temporal pulse broadening from GDD through dispersive media. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/group-delay-dispersion"
---

# Group Delay Dispersion calculator

Temporal pulse broadening from GDD through dispersive media.

Category: [Laser & Ultrafast](https://aperioptic.com/calculators)

Formula: `τout = τin·√(1 + (4·ln2·GDD/τin²)²)`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Input τ | `tau` | fs | 100 |
| GDD | `GDD` | fs² | 5000 |

## Result with the default inputs

- Output τ: 170.9331 fs
- Broadening: 1.7093×

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/group-delay-dispersion?tau=100`](https://aperioptic.com/calculators/group-delay-dispersion?tau=100). A unit other than the listed one goes in `<parameter>_unit`.

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

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