Fine structure of the inner electric field in semiconductor laser diodes studied by EFM

Electrostatic force microscopy in dynamical contact and non-contact modes i s employed to study the distribution of the electric field and capacitance at the cleavages of AlGaAs/GaAs based p-i-n laser diode heterostructures. T he fine structure of the inner electric field located at the i-waveguide of the laser heterostructure is revealed and investigated under forward and b ackward biases applied to the diode. The redistribution of the electric fie ld in favor of i-waveguide/p-emitter interface is observed at high level of injected current. When the injected current is increased, a growth of the capacitance signal at the i-waveguide is also detected which may reflect th e injected carriers distribution.