Where to Buy Dielectric Mirrors

• Do they have the required reflectivities or transmittivities at all relevant wavelengths for the intended angle of incidence and polarization direction? (Caution: reflectivity spectra change with the angle of incidence and are polarization-dependent, except for normal incidence!)
• Are they available with the required radius of curvature?
• Is the optical quality high enough? Consider surface quality (e.g. scratch & dig) and wavefront distortions. Also consider the optical homogeneity of the substrate, which may affect transmitted beams.
• May the reflection curves change with temperature or moisture?
• For high-power applications: are there thermal effects due to parasitic absorption and bulging? How about the optical damage threshold?
• For use ultrashort pulses: Is the chromatic dispersion appropriate?
• For output couplers: are there parasitic reflections from the back side? Avoid them with an anti-reflection coating there and/or with a wedge shape of the substrate?
• Are the substrate dimensions (diameter, thickness) appropriate?

In case that you need additional advice, consultancy from RP Photonics may be the solution.