Symbol Reference Sheet Symbol Meaning Frequency of the

Symbol Reference Sheet Symbol Meaning Frequency of the Input Signal Frequency of the Lock-in Reference Frequency of the Additional Sinusoidal Input Signal (or Coherent Noise) Frequency of the Input Signal’s Amplitude Modulation Amplitude of the Input Signal Amplitude of the Additional Sinusoidal Input Signal (or Coherent Noise) Percent of the Amplitude added to the Amplitude as Amplitude Modulation η Defined here (Increasing this value increases the intensity of this noise) Phase Angle of the Input Signal with Respect to the Reference Signal Time Constant (the “ms” that appears in this simulation stands for milliseconds) Output of the Lock-in Amplifier in Phase with the Reference before Low-pass Filter Output of the Lock-in Amplifier out of Phase with the Reference before Low-pass Filter Output of the Lock-in Amplifier in Phase with the Reference Output of the Lock-in Amplifier out of Phase with the Reference

Explanation of Simulation Inputs Input Signal Visualization of “Input Signal” amplitude with respect to time. Visualization of “Input Signal” power spectral density with respect to frequency. Brief Description of “Power Spectral Density” Graph

Explanation of Simulation Inputs Additional Sinusoidal Input Signal (e. g. , due to Coherent Noise) If this “Enable Sinusoidal Input” box is checked, an additional sinusoidal signal is introduced as part of the input signal. This box can be used, e. g. , to introduce a third or fourth input signal. This box is NOT used in this tutorial. Brief Description of “Power Spectral Density” Graph Visualization of “Input Signal” amplitude with respect to time. Visualization of “Input Signal” power spectral density with respect to frequency.

Explanation of Simulation Inputs Reference and Low-Pass Filter Settings τ The low-pass filter rolloff is set to 12 d. B/octave for the entire tutorial

Explanation of Simulation Inputs White Noise η Brief Description of White Noise

Amplitude Modulation ●

Explanation of Simulation Inputs Amplitude Modulation

Explanation of Simulation Outputs Visualization of the amplitude of the signal “After Mixing” but before the lowpass filter Visualization of the “After Mixing” power spectral density with respect to frequency

Explanation of Simulation Outputs

Schematic Diagram of Dual Channel Lock-in Amplifier Video Tutorial For more information go to: http: //www. iet. ntnu. no/courses/tfe 4160/lab/lock-in_amplifier. pdf

Low-pass Filter ● Video Explanation of Low-pass Filter

Low-pass Filter ●

Low-pass Filter ●

White Noise ●