Laser optics cleaning

Laser Optics Cleaning

Operates under the rules in ../../INSTRUCTIONS.md (reference-first, reference-only, interactive mode).

When to use this skill

When an operator suspects optic contamination (power loss, visible mark on the surface, or routine inspection finding) and is preparing to clean. This skill enforces the "don't clean it if it's not dirty" rule, walks through diagnostic inspection first, and only then escalates through the cleaning levels — always pausing for confirmation.

References to load at start

• references/laser_optics_cleaning.md — primary
• references/laser_optics_selection.md — for damage-vs-cleanable judgment

The three hard rules — apply throughout

Per laser_optics_cleaning.md §4:

Rule 1 — Don't clean optics that aren't dirty. Every clean is a chance to introduce a scratch.

Rule 2 — Never use unknown CDA. Use only an optic bulb blower or a canister labeled "clean air."

Rule 3 — One stroke, one tissue. Never re-use a tissue on an optic.

The skill must enforce these at the relevant gates.

Inputs to gather first

Ask the operator:

1. Which optic is suspected (focus lens, beam expander lens, F-θ, mirror, ...)?
2. Why is it suspected — power loss, visual indication, scheduled inspection?
3. Mounted or unmounted — is it accessible without breaking alignment?
4. PPE / cleanroom level in place.
5. Available cleaning supplies —
   • IPA grade (must be 99.99%-pure / laser- or spectroscopic-grade per laser_optics_cleaning.md §6)
   • When was the IPA bottle last replaced? (Open: today / Spill-prevention: last few days / Sealed: last week — per §6)
   • Lens tissues (clean, new pack)
   • Hemostats or tweezers
   • Optic bulb blower or canister labeled "clean air"

⚠️ The laser must be off, mechanically blocked, and the key removed before any optic is touched. Confirm explicitly.

→ Pause: confirm all inputs received and laser is safed. Then proceed.

---

Workflow

Step 1 — Diagnostic inspection FIRST (Rule 1)

Per laser_optics_cleaning.md §2.

Before touching anything, do a visual inspection:

• Reflect a ceiling light off the coating at a 45°–85° angle.
• Position so the background behind the optic is dark.
• Look for:
  1. Discontinuities, spots, scratches.
  2. Color changes at the beam-entry footprint (suggests coating change or sub-surface damage).

Three possible verdicts:

Verdict	Action
Looks clean	STOP. Don't clean. Re-measure power; if still down, look elsewhere (laser-troubleshoot).
Particles or film visible	Contamination. Proceed to Step 2.
Sub-surface damage / fracture / delamination	STOP. Replace the optic. Cleaning won't help.

Discoloration with no other defect is suspicious but not definitive — try cleaning, but be ready to replace if performance doesn't recover (per laser_optics_cleaning.md §1).

→ Pause: ask the operator which verdict applies. Branch accordingly.

Step 2 — Classify contamination type

Per laser_optics_cleaning.md §1.

Contamination	Cleaning levels
Particles only (dust, debris)	Levels 1–2: Air → Drop and Drag
Film / smoke residue	Level 3: Wipe
Mixed	Start at lowest level that addresses both, escalate as needed

→ Pause: confirm contamination type. Confirm cleaning supplies are present and ready.

Step 3 — Solvent freshness check (Rule 2 + §6 of cleaning ref)

A surface can never end up cleaner than the solvent used to clean it. (per laser_optics_cleaning.md §6)

Confirm:

• IPA is 99.99%-pure (laser- or spectroscopic-grade).
• IPA bottle is fresh enough:
  • Open-top bottle → must be replaced today.
  • Spill-prevention dispenser → within last few days.
  • Sealed bottle → within last week.

→ Pause: if solvent is older than the threshold for its container type, stop and request fresh solvent before cleaning.

Step 4 — Cleaning, escalating only as needed

Start with the gentlest method that has a chance of working.

Level 1 — Air

Per laser_optics_cleaning.md §5 Level 1.

Bulb blower or clean-air canister, upright.

⚠️ Never tilt the canister — tilting releases liquid propellant onto the optic. ⚠️ Never let frozen propellant land on the coating — thermal shock cracks coatings.

→ Pause: confirm Level 1 done. Did it resolve? If yes → Step 5. If no → Level 2.

Level 2 — Drop and Drag (flat surfaces only)

Per laser_optics_cleaning.md §5 Level 2.

For particles air can't dislodge, on flat surfaces. (Curved surfaces don't work well.)

1. Place optic on a clean surface, or hold it stable.
2. Lay a single lens tissue across the coating.
3. Apply 1–2 drops of IPA, let it spread through the tissue.
4. Drag the tissue with the wet edge trailing away from the optic.

The wet front lifts particles without the downward pressure that would otherwise grind them across the coating.

→ Pause: confirm Level 2 done. Resolved? If yes → Step 5. If no → Level 3.

Level 3 — Wipe (curved surfaces or stuck contamination)

Per laser_optics_cleaning.md §5 Level 3.

1. Fold a lens tissue to roughly the optic's width.
2. Grip near the fold with clean hemostats or tweezers, parallel to the fold.
3. Apply 1–3 drops of IPA on the fold, shake off the excess.
4. Drag slowly across the surface with light pressure.
5. As you drag, rotate the hemostat along the beak axis — this lifts particles up off the surface rather than smearing them across.
6. One stroke per tissue. Discard, refold, start fresh. (Rule 3.)
7. For multiple passes: always wipe in the same direction. Never reverse.

→ Pause: confirm Level 3 done. Resolved? If yes → Step 5. If no, evaluate:

• Small-aperture optic (micro-lens, fiber tip)? → Level 4.
• Full-aperture optic? → consider replacement.

Level 4 — Cleaning swabs (small areas only)

Per laser_optics_cleaning.md §5 Level 4.

Only for micro-lenses, fiber tips, ferrules. Small contact patch concentrates pressure — never use on full-aperture optics.

→ Pause: confirm.

What you must NOT use

Per laser_optics_cleaning.md §5 — "What you must not use":

• Eyewear or imaging-optics cleaning supplies — leave residues that survive at GW/cm² peak intensity.
• Microfiber cloths — shed fibers.
• Consumer "lens cleaner" formulations — contain detergent residue or polymer binders.

If the operator only has these available, stop the cleaning procedure and source proper supplies.

Step 5 — Verify

Per laser_optics_cleaning.md §2 + §7 (Decision Flow).

Repeat the inspection at 45°–85° in a dark background.

• Clean? → re-measure power if power loss was the original symptom. Compare to baseline.
• Still contaminated? → escalate one level, or scrap if approaching the swab/replace boundary.

→ Pause: report final verdict. Done.

---

Output

A cleaning record (markdown):

• Optic ID + position in the system
• Inspection verdict (Step 1)
• Contamination classification (Step 2)
• Solvent freshness confirmed (Step 3)
• Levels attempted: each one's result
• Final inspection result (Step 5)
• Power baseline comparison (if applicable)
• Operator notes

Save to outputs/laser-optics-cleaning/<YYYY-MM-DD>-<optic-id>.md.

---

Cross-skill links

• If contamination is found and the operator wants to verify the impact: hand to laser-power-measurement for a before/after reading.
• If contamination is suspected but inspection looks clean: hand to laser-troubleshoot — the issue may be elsewhere.
• If a sub-surface defect is found and replacement is required: refer to laser_optics_selection.md for spec verification of the replacement.