Editing Laser diode (section)

=== Separate confinement heterostructure lasers ===
[[File:Simple sch laser diode.svg|thumb|350px|Diagram of front view of a separate confinement heterostructure quantum well laser diode; not to scale]]

The problem with the simple quantum well diode described above is that the thin layer is simply too small to effectively confine the light. To compensate, another two layers are added on, outside the first three. These layers have a lower [[refractive index]] than the center layers, and hence confine the light effectively. Such a design is called a separate confinement heterostructure (SCH) laser diode.

Almost all commercial laser diodes since the 1990s have been SCH quantum well diodes. {{citation needed|date=April 2018}}