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Chemistry LibreTexts

Diode Lasers

  • Semiconductor materials layered to form a diode [2, a] serve as the gain medium.
  • Excitation is achieved by the passage of electric current (forward biased) through the diode p-n junction, which forms at the interface between semiconductors with different electronic doping levels.
  • Light emission occurs when electrons and holes in the vicinity of the p-n junction recombine following excitation.
  • The layered structure and high refractive index of semiconductor materials enables the laser optical cavity to be formed on the diode (see drawing, right).
  • Diode lasers are finding application in a wide range of areas, such as communications, medicine and chemical analysis (see Ref 2, 14, a, b).