Each effect that contributes to attenuation and dispersion depends on the optical wavelength.

As well as using optical wavelengths, the observatory also has extensive radio astronomy capabilities.

Blue here corresponds to 1.6 mm, and shows the cloud tops much as we see them at optical wavelengths.

"If we could implement this technique at optical wavelengths you wouldn't even be able to see that building down there with the naked eye."

In applications where a small focused beam is needed, the waveguide must be made narrow, on the order of the optical wavelength.

This collision appears to be forming a nebula that has been observed in the optical wavelengths.

He performed the first measurements of closure phase at optical wavelengths.

Depending on the type of modulated signal being carried, other optical wavelengths may be present.

This point is typically small, perhaps less than a fraction of a millimeter (depending on the optical wavelength).

The cluster is hidden by interstellar dust at optical wavelengths.