FIG 1 (IMAGE) Compuscript Ltd Caption Fig. 1 (a) The schematic of the proposed EO-DCS with sub-fm resolution and absolute frequency reference; (b) HCN absorption spectrum and (c) resonance spectrum of fiber F-P cavity measured by the proposed technique. Credit OEA Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.