Rasheed Abdur, Curtis Daniel B
Department of Chemistry and Biochemistry, California State University Northridge, 18111 Nordhoff Street, Northridge, California 91330-8262, USA.
Rev Sci Instrum. 2013 Jun;84(6):066109. doi: 10.1063/1.4811846.
Continuous-wave cavity ring-down spectroscopy offers several advantages over cavity ring-down spectroscopy with a pulsed laser, such as a higher repetition rate and decreased cost. However, the continuous-wave technique requires a more complicated experimental setup because the laser must be switched off rapidly when the intensity is high in order to observe a ring-down event. This note describes an inexpensive and simple latched comparator circuit that can be used to detect light intensity above a threshold value and send a signal to rapidly steer the beam out of the cavity and initiate a ring-down event. The latch eliminates switching noise by preventing the comparator from switching during the ring-down event.
与脉冲激光腔衰荡光谱法相比，连续波腔衰荡光谱法具有几个优点，例如更高的重复率和更低的成本。然而，连续波技术需要更复杂的实验装置，因为当强度较高时必须迅速关闭激光器，以便观察衰荡事件。本笔记描述了一种廉价且简单的锁存比较器电路，该电路可用于检测高于阈值的光强度，并发送信号以迅速将光束引导出腔并启动衰荡事件。锁存器通过防止比较器在衰荡事件期间切换来消除开关噪声。
