Two-in-One Laser

Daniel S. Burgess

Researchers at Bell Laboratories described in the Oct. 22 issue of Science a semiconductor quantum cascade laser that emits light at 6.33 or 6.5 µm with opposite bias polarities. Bell Labs' parent company, Lucent Technologies, has suggested that the capacity of optical networks could be doubled if the lasers can be designed to emit at shorter wavelengths.

The team grew the experimental light source through molecular beam epitaxy. An asymmetric injector region yielded different ground states of the miniband for opposite biases across the structure.