Semiconductor Lasers. Aashwinder Lubana Brian Urbanczyk Harpaul Singh Kumar Kunal Chopra. Introduction. L ight A mplification by S timulated E mission of R adiation. Laser light is monochromatic, coherent, and moves in the same direction.
Harpaul Singh Kumar
How Stuff Works http://science.howstuffworks.com/laser6.htm
Under forward bias (the p-type side is made positive) the majority carriers, electrons in the n-side, holes in the p-side, are injected across the depletion region in both directions to create a population inversion in a narrow active region.The light produced by radioactive recombination across the band gap is confined in this active region
Laser Focus World http://lfw.pennnet.com/Articles/Article_Display.cfm?Section=ARCHI&Subsection=Display&ARTICLE_ID=101065
and indium gallium arsenide nitride (InGaAsN).
VCSELs have been
constructed that emit
energy at 850 and
which is in the near
infrared portion of the
Metallic Reflector VCSEL
Etched Well VCSEL
Air Post VCSEL
Buried Regrowth VCSEL
The invisible beam from a high-power quantum cascade laser lights a match. It emits an optical power in excess of 200 mW from each facet at a wavelength of 8.0 µm.
The QCL can be regarded as an ‘’electronic waterfall’’. When a proper bias is applied and an electric current flows through the laser structure, electrons cascade down an energy staircase, and every time they fall down a step they emit a photon