Methods and efficiency of suppression of amplitude fluctuations exhibited by laser and superluminescence-emitting diodes

An investigation was made of the efficiency of suppression of excess amplitude fluctuations exhibited by laser and superluminescence-emitting diodes in the frequency range up to 1 MHz under conditions of antiphase addition of electrical signals in two channels for the transmission of radiation, providing a negative electrical feedback was used. Systems with abeam splitter ensured complete suppression of the excess noise of single-frequency laser and superluminescence-emitting diodes. Partial suppression of the excess noise in the case of multifrequency laser diodes was due to the spectral dispersion of the division coefficient of the beam splitter. When a feedback loop utilized the radiation emitted from the rear face of a crystal, the maximum noise suppression was achieved only for an "ideal" single-frequency single-mode laser diode.