Tips on generating entangled photon pair with SPDC entanglement source

[PokemanDude]

TL;DR Summary

My lab is trying to produce entangled photons with an SPDC entanglement source, but we're having trouble aligning the setup to produce entangled photons. What are some alignment tips for this equipment?

Hello! In my summer lab, me and my labmates are trying to generate entangled photon pairs using a spontaneous parametric down-conversion (SPDC) entanglement source with BBO crystals. We're using a 405 nm diode laser from Matchbox with model number 405L-21A. Our setup is as follows: we shine the laser through the SPDC entanglement source, and it is supposed to produce a pair of entangled photons (one is 847 nm and the other is 776 nm) and send them into one end of a fiber optic. The other end directs the entangled photons into a 50/50 beamsplitter. On one output side of the beamsplitter, we placed a filter that lets through 780 nm light and then a photon detector, and on the other output side, we placed a filter that lets through 850 nm light and then a photon detector. To detect entanglement, we are looking to see coincidences in the two detectors.
We're having trouble producing entangled photons, and we suspect that the laser, entanglement source, and fiber optic aren't aligned properly. What are some tips for aligning these?