Background

An adjustable semiconductor light source, such as lasers or light diodes, have a high demand for variable wavelengths in a controllable manner. Although there are methods to change the wavelength of a light beam, they are either impractical or uncontrollable. There is a need for an emission source which allows wide range electrical tuning of the emission wavelength for both laser and LED operation modes.

Technology

This tunable semiconductor is comprised of an optically active region with at least one cascaded stage. This cascaded stage has an injection section and an active section, which are separated by a barrier layer. They have multiple quantum well and barrier layers. Each active section supports electronic states, providing a lasting optical transition. A voltage is applied to the optically active region in order to pump electrons through it. By changing the voltage applied to the optically active region, the wavelengths can be modulated in the lasting optical transition. There is an area located on one side of the optically active region which has a grating structure; this allows wavelength selective reflections of optical waves to spread through the optically active region. A means for confining these waves to the active section is provided as well.

Advantages

This technology allows design and implementation of mid‑infrared semiconductor light‑emitting diodes and/or lasers electrically changeable in the wavelength region