Self-injection-locked thin-film regenerative laser amplifier

Organic lasers based on distributed feedback (DFB) microcavities have been extensively investigated. However, the application of these lasers is limited by their low output power and large beam divergence. Therefore, laser amplifiers are needed to achieve practically applicable laser intensity and controllable lasing modes for far-field applications. In this work, we report self-injection-locked laser amplifiers using the combination of a DFB microcavity and a Bragg reflector, where a high-reflection mirror acts as the Bragg reflector and its feedback supplies the external-cavity injection. The coherent coupling between the DFB microcavity and the Bragg amplifier is crucial for achieving high conversion efficiency and high-contrast transverse modes. An amplification factor larger than 20 and a single output laser spot with high contrast at have been achieved. Such an integration design of the self-injected DFB microcavity amplifier can be directly utilized in the realization of high-performance thin-film laser sources for practical applications.