A sensor interrogation unit in one embodiment includes a control module, a reading module, and a determination module. The control module is configured to control one or more lasers to provide a pulsed signal to at least one sensor. Each period of the pulsed signal has a first component having a first intensity and a second component having a second intensity that is lower than the first intensity. The reading module is configured to receive at least one return signal comprising reflections of the pulsed signal from the at least one sensor, to read one of the first component or the second component, and to provide frequency information based on the read reflections. The determination module is configured to determine at least one resonant frequency of the at least one sensor based on the frequency information.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
 This invention was made with government support under U.S. Government Contract Number DE-EE0002787 awarded by the Department of Energy, and under Government Contract Number DE-FE0010116. The U.S. Government may have certain rights in this invention.