# 📐 L2 Spec — Polarization Microscopy (Stokes / birefringence imaging) Mismatch-Only Spec
**ID:** `L2-013-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-013`](/artifact/l1/L1-013)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.45 · **Delta tier:** 5
> **⛓ On-chain block:** 41554158
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 256 – 4096 |
| W | px | 256 – 4096 |
| Lambda nm | nm | 400 – 900 |
| N pol states | — | 3 – 16 |
| Photon count | — | 50 – 20000 |
| Retarder drift | — | 0.0 – 0.1 |
| Polarizer alignment error | — | 0.0 – 0.05 |
| Intrinsic birefringence background | — | 0.0 – 0.2 |
## 2. Tolerance (ε)
**Type:** `fn`
```
24.0 + 2.0 * log10(photon_count / 50) - 15.0 * polarizer_alignment_error - 10.0 * retarder_drift
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.45 |
| Delta tier | 5 |
## 4. Fingerprint
`26be4949b113f686ddf5f9e93fa817f08fdba49be662960bb7a37a6f0f026697`
## 5. On-chain Registration
- **Chain hash:** `0x19deb62c735339ed0e87186c06f48111e79ad8d3b17884849848ef8bfbcbc6ba`
- **Chain tx hash:** `0x010ced8302fcdef12804d56b1d5bc688c750c4e3c97b83508067440eb6e11ef1`
- **Chain block:** `41554158`
---
## File Mapping
This bundle consists of: `L2-013-001.md`, `L2-013-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-013-001.md` | Source of truth — edit this | Human or LLM |
| `L2-013-001.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 `L2-013-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._