deletions | additions       diff --git a/In_order_to_better_read__.tex b/In_order_to_better_read__.tex  index ba72202..9907c62 100644  --- a/In_order_to_better_read__.tex  +++ b/In_order_to_better_read__.tex 
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In %In  order to better read the signals coming out from the photodiode (?), photodiode,  we applied a lock-in amplifier. A Lock-in lock-in  amplifier, also known as phase sensitive amplifier, is a powerful AC voltmeter. It only picks up frequencies that are around the reference frequency. In this way, we can filter out any white noise that would come from other sources, such as the 60 Hz signal from overhead lights, because we can specify the frequency range which we want the lock-in to amplify.   %In this way,  when the wavelength of our laser drifts away a little bit, the lock-in amplifier can fix this unexpected change. (NOT SURE-SHOULD ASK HIM) WHITE NOISE? In order to reduce the noise of our signal and therefore better read the signal coming from the photodiode, we used a lock-in amplifier. Lock-in amplifiers, also known as phase sensitive amplifiers, are powerful AC voltmeters. Lock-ins only pick up frequencies that are around our reference frequency, can be set to the frequency of our signal. Lock-ins can filter our white noise coming from other sources, such as the 60 Hz signal coming form the overhead lights. White noise is entirely random in both frequency and phase, so when averaging using the lock-in, the signal of the white noise averages to zero. Since lock-ins are also phase sensitive, and signal that is drifting in phase will be filtered out, which we would want because our signal should not be drifting in phase.