4 ms·
> He realized that rapidly changing the tilt angle of periodic facets on a diffraction grating, which can generate several replicas of the incident light travel
by h0l0cube 3y ago
> He realized that rapidly changing the tilt angle of periodic facets on a diffraction grating, which can generate several replicas of the incident light traveling in different directions, could present a way to sweep through different spatial positions to gate out frames at different time points.
My guess is the ‘sequence depth’ relates to the amount of diffraction gates. So perhaps all that’s needed is an ultrafast shutter to string together a long ‘movie’
- foota 3y agoThe diffraction grate (not gate, it is gating but it's a grate) has a number of possible diffraction modes dependent on the angular range of the DMD (an array of tiny mirrors that flip back and forth between two positions). In this case, there are 7 possible diffraction modes, and the sequence depth (the term for the number of frames) is 7 in reflection of this.
- h0l0cube 3y ago> not gate, it is gating but it's a grate I didn't mean to conflate the two, it's gating through a... 'grating'. Though the article and the paper do use the term 'diffraction gating'. > "Luckily, it is possible to accomplish this type of swept diffraction gate by using a digital micromirror device (DMD)—a common optical component in projectors—in an unconventional way," said Liang. "DMDs are mass-produced and require no mechanical movement to produce the diffraction gate, making the system cost-efficient and stable." "Diffraction-gated real-time ultrahigh-speed mapping photography" https://opg.optica.org/optica/fulltext.cfm?uri=optica-10-9-1223&id=538060 https://opg.optica.org/optica/fulltext.cfm?uri=optica-10-9-1...
- foota 3y agoThe terminology here is confusing, you could say it really grates on me.