Maker's Name: 
Sharp Corporation, Osaka, Japan
Where made: 

The first semiconductor diode laser was demonstrated in 1962 but continuous wave operation at room temperature was not achieved until 1970, earning Zhores Alferov and Herbert Kroemer the 2000 Nobel Prize in Physics.

In a diode laser, emisson of light from the anihilation of electrons and holes at a p-n junction is stimulated by a resonant wave trapped between dielectric mirrors deposited on the ends of the crystal.

The colour of the light depends on the type of crystal, the one most commonly used in CD players and other applications being the GaAlAs type, with wavelength of 780 nm. Fortuitously, such lasers can be tuned to the resonance absorption line of rubidium, making possible a whole range of atom optics experiments.

In this display, the top of the can that enclosed the laser has been removed. The actual laser is the tiny block, like a grain of salt, on the end of a fine gold lead. It has come loose from the heat sink to which it was attached.

Behind it is a square photodiode that monitors the small amount of light that leaks through the rear mirror, providing a signal that allows the laser output from the front mirror to be stabilised