We show that accelerated nonlinear imaging, such as stimulated Raman scattering and pump–probe imaging, is enabled by an order of magnitude reduction of data acquisition time when replacing the exponentially-weighted-moving-average low-pass filter in a lock-in amplifier with a simple-moving-average filter. We show that this simple-moving-average (box) lock-in yields a superior signal-to-noise ratio and suppression of extraneous modulations with short pixel dwell times, if one condition for the relation between the lock-in time constant and modulation frequencies is met. Our results, both theoretical and experimental, indicate that for nonlinear imaging applications, the box lock-in significantly outperforms conventional lock-in detection. These results facilitate the application of ultrafast and nonlinear imaging as a new standard for material characterization.

中文翻译：

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用于加速非线性成像的锁定探测器

我们表明，当替换锁定放大器中的指数加权移动平均低通滤波器时，加速非线性成像，例如受激拉曼散射和泵浦探针成像，可以通过将数据采集时间减少一个数量级来实现使用简单移动平均滤波器。我们表明，如果锁定时间常数和调制之间的关系有一个条件，那么这种简单的移动平均（框）锁定会产生出色的信噪比并抑制具有短像素驻留时间的外来调制频率满足。我们的理论和实验结果表明，对于非线性成像应用，盒子锁定明显优于传统的锁定检测。