Wafer-Level Laser Assemblies Having Extended Resonant Cavities

A laser assembly includes a set of one or more substrates having a first surface opposite a second surface. The set of one or more substrates defines a resonant cavity extension. The resonant cavity extension extends into the set of one or more substrates from an opening in the first surface. The laser assembly further includes a first reflector disposed within the resonant cavity extension and configured to reflect at least one wavelength of electromagnetic radiation received through the opening back through the opening; a laser having an active region configured to generate the at least one wavelength of electromagnetic radiation; and a second reflector. The active region is disposed in a resonant cavity extending between the first reflector and the second reflector. The resonant cavity includes the resonant cavity extension.