We wanted to be able to resolve the hyperfine structure, so we decided to slightly alter our setup. We fed the signal from the photodiode directly into the oscilloscope. The oscilloscope has a gain of 1,000,000. This is too much gain for the Doppler spectroscopy experiment where the incident laser beam had a power of 1 mW and saturated the oscilloscope voltage. With only 42.2 μW of incident power, this large gain factor gave us a voltage output of \(\sim 7-10 V\). If we increased the probe power to 50 μW, the oscilloscope saturated. In order to be able to resolve the hyperfine structure, we had to reduce the frequency range of our scan for each of the transitions. Since the oscilloscope takes a set number of points per second, reducing the range of the frequency scan allows us to get more data points per frequency increment. Although reducing the frequency range allows us to resolve hyperfine structure, it inhibits us from getting a good frequency read from the wavemeter over the range of the scan.