Configurable spectrometer

<p>For a long time I wondered whether it was possible to have a system that would allow to acquire spectral information only at <em>some</em> wavelengths. </p> <p>Something like this can be achieved with a filter wheel and several band-pass filters (this is the <a class="wikilink" href="/nanoqnt/">NanoQNT</a> approach). An AOTF could improve speed (and elegance) but it comes at implementation costs, since it would require some galvos to be added to the system. </p> <p>Another approach is what appeared on [[<a class="litnote tooltip" href="/literature/@gentner2023">@gentner2023<span class="tooltiptext">Compressive Raman microspectroscopy parallelized by single-photon avalanche diode arrays</span></a>]], where a DMD is pre-programmed to direct specific wavelengths into a point (or a series of) detector. Switching ON/OFF spectral bands becomes only a matter of selecting which pixels of the DMD are "ON" or "OFF". </p> <p>I think this approach is very elegant, since it removes the requirement of "panel design" common to <a class="wikilink" href="/flow_cytometer/">flow cytometer</a>. In essence, a tunable spectrometer can have "infinite resolution", in the sense that is only optically limited and not filter-limited. Moreover, the arrangement of mirrors can be tuned based no optimal selection for discrimination without additional costs. </p> <p>At hundreds of pixels in SPAD-Arrays, they would be a massive improvement on current channel-limited, camera-based, multi-spectral flow cytometers.</p>