A protocol using compact 3D printed micro-optical elements for protein identification from low-intensity amino-acid Raman signals

For high-speed Raman spectroscopy low intensity signals are a common problem. This complicates the identification of molecules even though in many applications the number of possible molecule outcomes is very limited. We present an approach to improve the amount of information gained with only a small number of detectors. Following the example of sequencing proteins with only 20 possible amino acids using only four detectors we first find optimized spectral regions that should be covered by one detector each to maximize the gained information. Next, we show a refractive-optical element that is capable of selecting and guiding the light from each of these spectral regions onto one detector each simultaneously. The element is fabricated using the benefits of two-photons grayscale lithography and later characterized in an optical experiment. The results match our simulations, indicating that our optical element indeed improves the performances of a real Raman spectrometer.