# 📐 L2 Spec — Thin Film Interference — transfer-matrix optical design Mismatch-Only Spec
**ID:** `L2-245-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-245`](/artifact/l1/L1-245)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41553992
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| Snr db | dB | 10 – 60 |
| N error | — | 0.0 – 0.05 |
| N layers | — | 1 – 100 |
| N wavelengths | — | 11 – 10001 |
| Substrate error | — | 0.0 – 0.05 |
| Thickness error | — | 0.0 – 0.05 |
## 2. Tolerance (ε)
**Type:** `fn`
```
22.0 + 0.3*SNR_dB - 30.0*thickness_error - 40.0*n_error - 20.0*substrate_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`ad6d68efdf4354323cfa12440cd22b881078b35239f87d0cb1467ddc69483c76`
## 5. On-chain Registration
- **Chain hash:** `0x13cd39a2648d4fbc0dc5a56aff15f889b00f3b51cf9c50dfa3d688bf00996419`
- **Chain tx hash:** `0x44fbc58fcd2873cabbfb07f8f4e9b6cf8c573a832ea96914a35cbd7ac862d69a`
- **Chain block:** `41553992`
---
## File Mapping
This bundle consists of: `L2-245-001.md`, `L2-245-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-245-001.md` | Source of truth — edit this | Human or LLM |
| `L2-245-001.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 `L2-245-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._