The future evolution of photonics, for a wide spectrum of applications ranging from
established optical telecommunications to emerging opportunities such as biotechnology,
reprographics and projection displays, will depend on availability of compact, rugged,
efficient and inexpensive lasers which deliver high power, good beam quality, excellent
wavelength stability, low noise and long lifetime in the near infrared and visible regions.
This combination is not readily available from either of the traditional classes of
semiconductor laser, edge-emitters and vertical cavity surface emitters (VCSELs). Here
we describe a novel class of laser based on geometry similar to VCSELs but controlled
by an extended coupled cavity. These devices are scalable to high powers while
maintaining fundamental spatial mode performance, a feature that is essential to efficient
coupling into a single mode optical fibre or waveguide, or long range propagation in free
space. They are also ideally suited to mode locking, gain-switching and intracavity
frequency conversion, among other applications.