Electro-optically modulated lasers: pulse energy and contrast enhancement derived from theoretical spectrum

Abstract: In this article, we derive analytically the complex optical spectrum of a pulsed laser source obtained when a frequency comb generated by phase modulation is input into a synchronized intensity modulator. We then show how this knowledge of the spectrum may help to achieve unprecedented accuracy during the experimental spectrum correction step usually carried out with an optical spectrum processor. In numerical examples, for a given average power we present up to a 75 % increase in peak power and an enhancement of the extinction ratio by at least three orders of magnitude. This method also enables large-factor rate-multiplications of these versatile coherent sources using the Talbot effect with negligible degradation of the signal.