The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Measurements of the effect of weak feedback on single-frequency 1.5 μm lasers are reported. The results are found to agree well with published theoretical analyses. Sensitivity to feedback is found to be the same for DFB, C3 and Fabry-Perot lasers. These results indicate that coherent systems using DFB lasers may require greater than 50 dB isolation.