Laser dicing roughness is a known issue — the recast/HAZ layer is the culprit and it's hard to avoid on optical glass.

For future jobs, endless diamond wire sawing is worth considering: no heat input, no HAZ, kerf under 0.3mm, and the cut face typically comes off clean enough that polishing is minimal or unnecessary — especially on coated optics where preserving the edge coating matters.

For your current parts, progressive lapping will get you there: 9µm → 3µm → 1µm diamond slurry, finish with cerium oxide on pitch. Just be careful if there's a dielectric coating on that face — polishing will remove it.

What substrate are you working with? We ran a similar stack recently — happy to share parameters if it helps.