Using a Lock-In Amplifier
نویسنده
چکیده
In this lab, we explore the principles of the use of a lock-in amplifier, using a He-Ne laser, light chopper, and a photodiode as the lock-in input. We explain and use the concepts of phase sensitive detection, dynamic reserve, and time constants to determine both the range of linearity of the photodiode in use, as well as the frequency response of the photodiode. Furthermore, we determine whether the frequency response of the photodiode is independent of intensity. Photodiode output voltage data as measured on the lock-in (varying both frequency and intensity) are presented.
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