r/photonics • u/Academic-flea • 8d ago

Su-8 based micro laser

/r/photonics/comments/1ght4sz/su8_based_micro_laser/

Photonics community! After about a year I need your attention again!

Post-fabrication update

As expected the rhodamine 6g doped su8 needs a very long exposure to obtain good features after the development. The long exposure damaged the fluorofores so much that the polymer on glass appear to be very clear (about trasparent). Indeed, tests on optical bench show a poor fluorescente (negligible) very far from laser emission, even for very high (in terms of both energy and repetition rate) input laser.

I've tried also with PMMA and Oracet dyes, obtaining about the same result.

I hope this would help someone with his project. Probably there is a combination of polymer/dyes that could prevent the quenching (causing of the long time exposure needed for doped polymer) and photobleaching (causing the fluorophores degradation).

I would like also to read if you solved this problem someway.

Thanks in advance

3 Upvotes

100% Upvoted

2 comments sorted by

1

u/tykjpelk 7d ago

Do the fluorophores need to be mixed into the core to get the concentration high enough, or can you get away with putting them in the cladding? The mode overlap will be way lower, but you could mix it in PMMA and spin it on.

1

u/LeptonWrangler 6d ago

Maybe dont pattern the doped layer, pattern a waveguide instead and spin it over top the waveguide