Contribution of Amplified Spontaneous Emission to Output Signals of Laser Active Optical Systems

The paper studies the composition of output signals of metalvapor laser active optical systems under various operating conditions. The effect of the time characteristics of these systems on the output signal composition is experimentally estimated. A technique for determining the contribution of amplified spontaneous emission (ASE) to the output signals of self-adjoint system and system with independent illumination source is suggested. An optimal time of input signal arrival to the active medium of an amplifier for ensuring the maximal signal/noise ratio is determined. ASE is completely suppressed in the system with independent illumination source at a time delay of −4.3 to +25.8 ns. Complete suppression in the self-adjoint system was not achieved. The minimal ASE value in the self-adjoint system was 80 mW, i.e., ~2% of output signal power. The results can be useful in studying the amplification characteristics of active metalvapor optical systems and in visual-optical diagnostics in laser monitors on their basis.