Background Removal in Stimulated Emission Imaging with Dual Frequency Lock-in Detection

• Main Authors: I-Che Chen, 陳逸哲
• Other Authors: Fu-Jen Kao
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/90930648179590241955

碩士 === 國立陽明大學 === 生醫光電研究所 === 104 === Recently the pump-probe has many different kinds of development and application, and this technique has combined with microscopy to observe the tissue and cell. In this work, we use the mechanism of stimulated emission and dual frequency modulation to remove the background signal. In this work, we are applying a new generation of digital signal processing (DSP) based lock-in amplifier (HF2LI, Zurich Instrument) for stimulated emission microscopy. In addition to modulating the pump beam (at f1), the probe beam is also modulated at a different frequency (f2). The demodulation is then carried out at the sum of the two frequencies, f1+ f2. In this way, the DC background that is often attributed to the spontaneous emission of the pump beam is effectively removed. The double modulation enables versatile and unprecedented data acquisition in scanning microscopy that uses the technique of pump-probe configuration.