Amplified spontaneous emission in distributed feedback active microcavities fabricated by the sol–gel dip-coating method

Abstract

Amplified spontaneous emission (ASE) is demonstrated in a distributed feedback (DFB) active microcavity, formed by rhodamine B molecules in a Bragg grating (BG). The BG was fabricated by alternately depositing titanium dioxide and silicon dioxide sol–gel thin films. The reflectance spectrum of BG simulated by the transfer matrix method was consistent with experimental results, demonstrating that the BG had good periodic structures. With rhodamine B molecules embedded, the ASE was observed from the DFB active microcavity in optical pumped conditions. The full-width-half-maximum and threshold of ASE were 7.5 nm and 0.2 mJ/pulse. The slope efficiency of 3% was measured. The DFB active microcavity is promising for low-cost ASE.