Future Experiments and Tips
Future MXP SPR Experiments:
We don't recommend trying to explore thickness dependance within the scope of a 15 week project. If thickness dependance is what you want to explore, try to make more than five different samples. Truly, we would recommend around 15 different thicknesses in order to meaningfully describe the relationship between thickness and SPR over the range of about 30-100 nm, so do as many as you can.
One recommendation we do have for an MXPII project on SPR would be exploring how different chemical residue films affect resonance. We started exploring how isopropanol residue affect our resonance near the end of our project as it was used in our cleaning process for our samples, and found some pretty interesting preliminary results. Perhaps an attempt to optimize resonance conditions dependent on a variety of chemical films (acetone, isopropanol, etc.) would be an interesting project!
Another recommended experiment might be to explore how quickly silver samples oxidize, we've found sources that say the angle of SPR can change over a degree in as little time as a month for a 40 nm sample! (Source)
General Tips/Tips for Finding Resonance:
Consistently finding resonance is a skill that takes time and practice to develop, but hopefully some of the tricks we learned along the way can help you! Our recommendations include:
Make your samples as soon as you can! The samples from semesters' past can he helpful in developing a process for data collection, but it is unlikely you will be able to see any real resonance on those samples; don't dwell.
Always handle your samples with gloves on.
Never touch the Silver on your sample (or whatever conductor you may be using) as it fingerprints and/or comes off very easily.
Label the side of your sample slide that has the silver on it.
When resonance occurs, oftentimes if viewing your sample from the back, you'll be able to spot "wings" coming from where the laser is hitting the sample as shown in the photograph below.
Document everything in photos! Take photos of your set-up and equipment, they tend to be super useful!
SPR will show up as a dark vertical line through your sample; don't mistake scratches or other residue for SPR, even if the polarizer seems to make them appear/disappear.
If you aren't actively collecting data from a sample, keep it closed in its case to prevent it from getting damaged or dirty.
MATLAB's online collaborative format is super helpful!