DarkSucker

Joined 4 years ago

Karma
47
Submissions
25
Member since
Apr 3
I work with light: science, engineering, and ideas.
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Recent submissions

Comment · 10 months ago
Comment · 1 year ago
Each pixel of such a scanner would need to somehow scan the spectral content. For example, imagine an array of fibers each transporting light from image plane pixel coupled to a spectrometer (bulky, expensive). Slit (a.k.a. push broom) scanners take each pixel of its slit and disperses the light perpendicular to the slit onto a 2D sensor array (more compact, 1D mechanical scan required). I recall seeing spectral (color) filters made from dispersive materials sandwiched between rotating polarizers to filter (scan) the light entering camera (expensive, compact).
Comment · 1 year ago
Sounds great, but I often find myself wondering "where's the catch?". There's not enough info in the abstract judge for myself whether the idea has legs. I'm sure it'll get more press if there's something to it.
Comment · 1 year ago
As I read the article. The tsunami wave (water) displaces air at the surface and creates a sound wave, and gravity waves, that travels to the upper atmosphere. These waves then interact with electrons in the upper atmosphere.
Comment · 1 year ago
Thanks. I wasn't thinking of enums. To the extent one designs a trait to use an enum type (or the enum to satisfy the trait), one wins. But it seems impossible to avoid code to handle all future {type, op} combinations. The nice thing I've seen with Rust is the ability to add to what's been done before without breaking what already works. I'm thinking of "orphan rules" here.
Comment · 1 year ago
The article's `expression problem matrix` section states that the goal is make it `easy to add ops` and `easy to add types`. My learning of Rust so far indicates Rust satisfies both: traits satisfies the `ops` problem for all traits you want to support the op, and Rust's implementations (impl) solves the problem of adding types. Of course, for each new {op,type} combination, one must write the code, but Rust allows you to do that with its trait and generic systems. Am I missing something important?
Comment · 1 year ago
I think the alternative is shown in figure 2. SiN (silicon nitride) is different from optical fiber. Both versions shown in figure 2 lack detail, especially in the small boxes labeled GC, Mirror, and PD. Depending on the details, one might put micro optical assemblies between or in those boxes in the figure. In any case, SiN waveguides are small, so you can pack many lanes in a small space.
Comment · 1 year ago
Can anyone speak to the image processing used? In particular, how is depth inferred from a single 2D image? It seems to me one would need both depth and angle over the field of view to back out the lens focal length. The EXIF format doesn't seem to contain meta data helpful to the focal length calculation.
Comment · 1 year ago
That link made my day! Thank you. From what I read, their builds perform better than the originals, and they even make landscape versions. Woo hoo! RPN rules in my book. I picked up an HP 32 before they were gone forever, but I've been afraid to use it. It's great to know about SwissMicros; they'll get my business soon.
Comment · 1 year ago
Thanks! I'm sick and couldn't bring myself to do the wavelength calculation. Your comment helped my thoughts. I think people working on microwave equipment (frequency counters, ...) work in Hz.That's probably why they used the term.
Comment · 1 year ago
Neither the article nor official link gave much optical design detail. Here's my guess. A (substantially) radially symmetric system comprising a wide-angle positive-short-focal-length first lens followed closely by a negative-short-focal-length whose diameter is small (thus covering a small range of angles, in the center field of view, from the first lens). A single central sensor behind the negative element is for telephoto images, while a collection of sensors distributed radially around the first lens and off axis capture wide angle images.

Imagine a low-index ball lens in contact with a thin high-index negative lens. That's the idea. I'm sure the real design uses multiple surfaces/elements for each lens, and I'm sure it's hyper-optimized. I'm interested to learn how close my guess is to reality.

Apologies for the complex wording to describe geometry.

Comment · 2 years ago
The new design design uses on axis mirrors to image the photomask onto the wafer, and on axis mirror systems are far easier to design and fabricate compared to zig zag (off axis) systems. I've never designed an EUV system, and I guess that Shintake's team had to solve some materials or optical coating technology issues that allowed them to consider the simpler on axis design. Having worked on zig zag and on axis designs in the IR and VIS range, I can say that Shintake's design will be much (orders of magnitude?) easier to align and assemble.
Comment · 2 years ago
It seems to me this data could be used to correlate a species/genus to a location if one knows where the samples came from. If one also knows the date of the geological strata the samples came from, then one also has a date correlation. A particular animal at a site at some time seems like information a researcher can use.
Comment · 2 years ago
Can someone provide/link-to a principle of operation? I looked at references (https://www.dragonflytelescope.org/publications.html) but they point to publications that look to be behind pay walls.

In particular, I don't see how N co-aligned cameras is any different than N images taken in sequence with one camera (averaging over noise), other than a reduction in time required to take N images with one camera.

Comment · 2 years ago

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