Measurements of laser properties of organic semiconductors to predict organic laser thresholds

In the context of the quest of organic laser diode, we propose a method to compare organic gain semiconductors in terms of laser threshold before integrating them into laser cavity. This method is based on three types of measurements for each material: 1-measurements of absorption and photoluminescence spectra to evaluate the re-absorption, 2-measurement of fluorescence lifetimes linking the potential laser gain to the current in the diode and 3-measurement of the gain of the amplified spontaneous emission. This approach is validated by laser threshold measurements carried out under optical pumping for two organic compounds DCM and DCJTB deposited on laser cavities.