# 📐 L2 Spec — Two-Photon Microscopy (chi-3 NLO excitation) Mismatch-Only Spec
**ID:** `L2-009-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-009`](/artifact/l1/L1-009)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.45 · **Delta tier:** 5
> **⛓ On-chain block:** 41554157
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 – 2048 |
| W | px | 128 – 2048 |
| Z | — | 16 – 512 |
| Na | — | 0.6 – 1.1 |
| Pixel nm | nm | 200 – 1000 |
| Lambda ex nm | nm | 800 – 1060 |
| Peak photons | photons | 20 – 2000 |
| Pulse width fs | — | 50 – 500 |
| Sample scattering | — | 0.0 – 0.5 |
| Laser pointing jitter | — | 0.0 – 0.02 |
## 2. Tolerance (ε)
**Type:** `fn`
```
19.0 + 2.0 * log10(peak_photons / 20) - 8.0 * sample_scattering - 2.0 * log10(pulse_width_fs / 50)
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.45 |
| Delta tier | 5 |
## 4. Fingerprint
`6efff209cf99c99839267f55ac45328fff801a5d6a5d872ee649904aa9ececc9`
## 5. On-chain Registration
- **Chain hash:** `0x1344f6b72ff30167521f32661679aae5e2f359368b955d870dd5a03cddcdf654`
- **Chain tx hash:** `0x8d83e95323174868d2c45fc22bba6c39661bc2138b6b56f538f463eb77b6c4a8`
- **Chain block:** `41554157`
---
## File Mapping
This bundle consists of: `L2-009-001.md`, `L2-009-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-009-001.md` | Source of truth — edit this | Human or LLM |
| `L2-009-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-009-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._