Tunable Lasers are key-components for Wavelength Division Multiplexing optical communication applications at 1.55µm. In this paper, we report the analysis of the correlation function between the active or passive section electrical noise power spectral density and the optical noise power spectral density. We performed this study in two opposite SMSR ("Side Mode Suppression Ratio") configurations, i.e. high SMSR (monomode configuration) values and low SMSR (mode competition configuration) values, in a low to medium frequency range, from 1Hz to 500kHz. The active section/optical beam correlation measurements are given as reference in order to allow a qualitative and quantitative comparison with the passive section/optical beam correlation results. The new field of investigation is the correlation between the optical beam noise and the Bragg section electrical noise. The aim of this analysis is to show the contribution of the Bragg section electrical noise into the beam optical noise. Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/24/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Proc. of SPIE Vol. 5111 247 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/24/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx