RbQ Baseline Requirements:

Substrate

1" diameter

~0.2" thick

Wedge 0.5°

High Purity UVFS

Side 1:

Curved (target RoC = 0.215 m)

Side 2:

Flat

Polishing

Side 1:

Superpolished surface (target < 1Å rms) over inner 80% of diameter with 10/5 scratch dig with best effort for 0/0

20/10 scratch dig outside central 80% diameter

Side 2:

< 5 Å rms over outer 80%

< lambda/10 at 632.8 nm for central 80%

Coating

Side 1:

~99% reflectivity for 1550 nm light, HR coating for shorter wavelength (TBD)

Polarization: circular?

AOI: 3°

Need low loss for 1550 nm coating (< 20 ppm)

Likely need secondary coating for 387.5 nm with less stringent requirements

Side 2:

AR with < 0.1% reflectivity (best effort for 0% reflectivity)

Unknown exact cavity design with HR vs. couplers

Misc

Procurement of optics be done with 1 to 3 suppliers, preferably 1

See GQuEST Cavity Optics Page for specs

Suppliers

Summary: Coastline + Perkins do curved substrates and polishing

Coastline and Perkins also does polishing of curved substrates

Not clear whether LaserOptik and FiveNine Optics can do minimum curvature specs

Coastline

Does curved substrates

1550 nm coating with specs

775 nm or 387 nm coating also with specs

Cannot measure loss

Perkins

Does curved substrates and coatings

LaserOptik

Does not make substrates (and doesn't seem to polish)

Only coatings

Not clear what the minimum radius of curvature is

FiveNine optics

Does not make substrates (and doesn't seem to polish)

Only coatings

Not clear what the minimum radius of curvature is

Thorlabs

TBD, not the most promising

Newport

Only off the shelf parts