Literature/202310101212 stereo darkfield interferometry

<ul> <li>Source: [[literature/<a class="litnote tooltip" href="/literature/@rieu2021">@rieu2021<span class="tooltiptext">Parallel, linear, and subnanometric 3D tracking of microparticles with Stereo Darkfield Interferometry</span></a>|<a class="litnote tooltip" href="/literature/@rieu2021">@rieu2021<span class="tooltiptext">Parallel, linear, and subnanometric 3D tracking of microparticles with Stereo Darkfield Interferometry</span></a>]]</li> <li>Tags: <a href="/tags/Instrumentats">#Instrumentats</a> <a href="/tags/nanoparticle-tracking-analysis">#nanoparticle-tracking-analysis</a> </li> </ul> <p>One of the biggest issues with 3D <a class="wikilink" href="/nanoparticle_tracking/">nanoparticle tracking</a> is that instruments lack sufficient resolution (both temporal and spatial). <a class="wikilink" href="/stereo_darkfield_interferometry/">Stereo Darkfield Interferometry</a> (SDI) solves some of the issues by using a combination of techniques in a "simple" to assemble microscope. </p> <p><img alt="images/Pasted image 20231010121755.png" class="wikiimage" src="/images/pasted image 20231010121755.png" /></p> <p>By adding a combination of a <a class="wikilink" href="/dark-field_microscope/">dark-field microscope</a> (in the image above using two superluminescent LED's) with a slit configuration (right at the tube-lens), with two wedges that allow to separate the stereoscopic interference pattern, they can achieve full 3D localization with better than $nm$ accuracy. </p> <p>I find it very interesting that the noise for the localization is given by:</p> <p>$$ \sigma_i^2 &gt; \frac{1}{g_i^2N}\frac{1}{\int \frac{f'(i)^2}{f(i)}di} $$</p> <p>$g$ is related to the magnification, $N$ to the number of photons, but the interesting argument is the integral of the intensity profile ($f$). Since it depends on the derivative (squared!), the quicker the profile changes, the higher the precision. </p> <blockquote> <p>Is perhaps these way of considering accuracy related to the way <a class="wikilink" href="/minflux/">minflux</a> works? </p> </blockquote> <p>I also wonder if a method like this can be combined with a technique like <a class="wikilink" href="/sp-iris/">SP-IRIS</a>? In principle the interference pattern depends on the refractive index of the particle, which could be used for singe-shot sizing? </p> <p>A different implementation, without the "stereo" is <a class="wikilink" href="/literature/202405221125_nanofluidic_scattering_microscopy_(nsm)/">202405221125 Nanofluidic Scattering Microscopy (NSM)</a></p>