# meep-getting-started

> resolution = 20 dpml = 1.0

- Author: Tao E. Li
- Repository: TEL-Research-Group/meep
- Version: 20260207225459
- Stars: 0
- Forks: 0
- Last Updated: 2026-02-08
- Source: https://github.com/TEL-Research-Group/meep
- Web: https://mule.run/skillshub/@@TEL-Research-Group/meep~meep-getting-started:20260207225459

---

---
name: meep-getting-started
description: Quickstart Meep/PyMeep usage: choose Python vs Scheme vs C++, set units, build a minimal simulation (cell/geometry/source/PML/run), and avoid common first-run pitfalls.
---

# meep: Getting Started

## Route The Question
- Installation/build issues: use `meep-build-and-install`.
- Time-stepping / outputs / stopping conditions / parallel runs: use `meep-simulation-workflows`.
- Flux/DFT/near2far/eigenmodes/adjoint/frequency-domain solver: use `meep-api-and-scripting`.
- Geometry/material modeling (dispersion, smoothing, symmetry, GDS): use `meep-inputs-and-modeling`.

## Quick Triage Questions (Ask Early)
- Interface: Python (PyMeep) vs Scheme vs C++?
- Dimensionality: 1D/2D/3D or cylindrical?
- Units: what is the chosen length unit `a` (e.g. 1 um), and what wavelength/frequency band?
- Boundary conditions: PML vs periodic/Bloch (`k_point`) vs metallic?
- Output goal: fields/flux spectrum/modes/forces/near-to-far?

## Minimal PyMeep Skeleton (2D, cartesian)
Use this as the default starting point and then specialize:

```py
import meep as mp

resolution = 20
dpml = 1.0

cell = mp.Vector3(16, 8, 0)
boundary_layers = [mp.PML(dpml)]

geometry = [
    mp.Block(
        size=mp.Vector3(mp.inf, 1, mp.inf),
        center=mp.Vector3(),
        material=mp.Medium(epsilon=12),
    )
]

sources = [
    mp.Source(
        mp.GaussianSource(0.15, fwidth=0.1),
        component=mp.Ez,
        center=mp.Vector3(-7, 0),
    )
]

sim = mp.Simulation(
    cell_size=cell,
    boundary_layers=boundary_layers,
    geometry=geometry,
    sources=sources,
    resolution=resolution,
)

sim.run(
    mp.at_beginning(mp.output_epsilon),
    mp.to_appended("ez", mp.at_every(0.5, mp.output_efield_z)),
    until_after_sources=mp.stop_when_fields_decayed(50, mp.Ez, mp.Vector3(), 1e-9),
)
```

## Units And "What Numbers Mean"
- Pick a length unit `a` (e.g. `a = 1 um`). All geometry values are in units of `a`.
- Frequency `f` in Meep is `a / lambda0` (vacuum wavelength). Equivalently: `lambda0 = 1 / f`.
- Time is in units of `a/c` (with `c=1` in Meep units).
- Use `wavelength=...` for sources if that is more natural than `frequency=...`.

## First-Run Pitfalls (Most Common)
- Leave padding between sources/geometry and PML; don’t interpret fields inside the PML.
- Start with a broadband Gaussian source; only switch to CW once you trust the setup.
- Do not guess a run time; use `until_after_sources=...` with a decay condition.
- Converge: increase `resolution`, and increase/double PML thickness until results stop changing.

## Primary Documentation References
- `doc/docs/Introduction.md`
- `doc/docs/C++_Tutorial.md`
- `doc/bfast/fixed_angle_broadband_simulations_in_Meep.md`
- `doc/docs/Scheme_Tutorials/Basics.md`
- `doc/docs/Python_Tutorials/Basics.md`

## Workflow
- Start with the primary references above.
- If details are missing, inspect `references/doc_map.md` for the complete topic document list.
- Use tutorials/examples as executable usage patterns when available.
- Use tests as behavior or regression references when available.
- If ambiguity remains after docs, inspect `references/source_map.md` and start with the ranked source entry points.
- Cite exact documentation file paths in responses.

## Tutorials and examples
- `python/examples`
- `scheme/examples`

## Test references
- `tests`

## Optional deeper inspection
- `python`
- `src`

## Source entry points for unresolved issues
- `python/solver.py`
- `python/simulation.py`
- `src/meepgeom.hpp`
- `src/meepgeom.cpp`
- `src/meep_internals.hpp`
- `src/meep.hpp`
- `src/fix_boundary_sources.cpp`
- `python/meep.i`
- Prefer targeted source search (for example: `rg -n "<symbol_or_keyword>" python src`).