​​​​​​​Chyeguide

Laser Diode Structure

​A schematic diagram of a laser diode is shown in Fig. 1. It is

• p-n junction diode for injecting electrons and holes  into the active layer.
  
• optical waveguide  (the active layer is sandwiched between the p and n cladding regions)
  

Photons generated in the active layer propagate in the waveguide and partially reflected back by the two facets (or a grating), obtaining feedback to reach lasing)

Laser Diode Basic Static Characteristics

• The diode voltage (V) increases as the injection current (I) increases , as is shown in Fig. 2. The differential resistance (dV/dI) shows an abrupt change around the threshold due to the carrier density clamping caused by lasing.
  
• Electrical threshold current (Ith) (maximum d/dI (dV/dI) point) 
  

Tutorials