The hottest Optics Substack posts right now

And their main takeaways
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Top Science Topics

Anything Will Lase If You Hit It Hard Enough

Maximum Effort, Minimum Reward • 894 implied HN points • 14 Mar 26
🔬 Science Optics
  1. A true laser needs three things: a gain medium for stimulated emission, a pump that creates a population inversion, and a cavity that gives feedback so one wavelength is amplified. Stimulated emission makes identical photons so the light can cascade into a coherent beam.
  2. Almost anything with suitable electronic states and some feedback can be made to lase if you pump it hard enough — people have made lasers from dyed jell‑O, peacock feathers, biological tissue, edible microlasers, and even parts of planetary atmospheres.
  3. Practical and fundamental limits stop some things from lasing: losses that grow with pump power and the rapidly shrinking upper‑state lifetime at high frequencies mean materials like silicon and very high‑energy ranges (UV, X‑ray, gamma) are effectively impossible to lase with realistic pumps.

Drones and Lasers - what could possibly go wrong?

atomic14 • 519 implied HN points • 22 Jan 26
đź•ą Technology Optics
  1. Pairing drones with lasers can be exciting but brings real safety and legal risks.
  2. Buying a big batch of parts from overseas often leaves you with a chaotic pile of gear and forgotten items.
  3. This is typical maker/DIY territory — hands-on tinkering that can lead to unexpected results.

Optical Conversion of CMOS <> Superconducting Signals

Tapa’s Substack • 119 implied HN points • 10 Sep 24
đź•ą Technology Optics
  1. There's a new idea to use light to switch superconducting signals with CMOS circuits. This could help in areas like quantum computing and sensors.
  2. Using light for this switching can provide thermal isolation, which is a big advantage. It makes the connection between different technologies safer and more efficient.
  3. Two methods to switch are discussed: thermal and non-thermal. Non-thermal switching might be better because it's more efficient, using light directly instead of heating things up.

Why Meta's AR/VR Dreams Need China's Goertek

ChinaTalk • 326 implied HN points • 07 Jan 26
đź•ą Technology Optics
  1. Goertek is more than a parts supplier — it assembles Meta’s headsets, runs centralized procurement, and manages a huge network of component makers, giving it outsized influence over costs and timelines. This makes it hard to replace even though its direct component value looks small.
  2. Meta is trying to diversify suppliers and move some production out of China, but swapping individual components isn’t the same as rebuilding an entire supply chain, so true decoupling remains difficult.
  3. Key XR parts like waveguides, pancake lenses, and optical engines are yield-constrained and dominated by a few firms (notably Goertek and Sunny Optical), creating capacity bottlenecks that drive shortages and limit product availability.

EUV With Fewer Mirrors?

The Asianometry Newsletter • 3214 implied HN points • 28 Oct 24
đź•ą Technology Optics
  1. A new proposal suggests using fewer mirrors in EUV lithography machines to improve efficiency. This could help capture more light and reduce costs in the chip-making process.
  2. The new system builds on existing technology and aims to complement rather than compete with ASML's machines. It's about making improvements instead of replacing what's already working.
  3. There's still a long way to go before this new design can be a reality. Many technical challenges need to be solved before it can be tested in actual lithography machines.
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New colors without shooting lasers into your eyes

DYNOMIGHT INTERNET NEWSLETTER • 750 implied HN points • 17 Jul 25
🔬 Science Optics
  1. Our eyes have different cells that help us see color, but they sometimes overlap, making it hard to see some colors clearly. This overlapping means we usually never activate only one type of color cell at a time.
  2. Some researchers are using lasers to stimulate specific color cells in our eyes, allowing people to see colors they typically wouldn't be able to experience. This can create unique visual experiences that challenge our understanding of color.
  3. Optical illusions might help us see new colors too, without lasers. However, whether these illusions can truly take us beyond what we usually see with our eyes is still an open question.

Lies, damned lies, and photodiodes

lcamtuf’s thing • 2040 implied HN points • 09 Dec 24
đź•ą Technology Optics
  1. Photodiodes can have a wide range of response speeds, and the advertised specs often don't tell the whole story. It's important to understand how they are tested, as this can affect their performance.
  2. When building precise measurement devices with photodiodes, two types of currents play a role. One is fast, while the other can take much longer to settle down, impacting the overall signal quality.
  3. Using techniques like reverse bias can improve performance, but some effects are inherent to the photodiodes themselves. Understanding these limitations is key for achieving accurate measurements.

How To See Impossible Colours

Everything Is Amazing • 733 implied HN points • 21 Feb 23
🔬 Science Optics
  1. By focusing your eyes in a certain way, you can see impossible colors like red-green or blue-yellow.
  2. Seeing colors like Stygian Blue or Hyperbolic Orange challenges our understanding, as they seem darker or brighter than physically possible.
  3. Experimenting with how you view colors can lead to unique perceptual experiences, expanding the boundaries of human vision.

HyperX Topology for Photonic Wafer Scale Integration

Tapa’s Substack • 59 implied HN points • 17 Dec 23
đź•ą Technology Optics
  1. Using the HyperX topology can be a good choice for connecting photonic wafer-scale systems, helping to improve efficiency and lower costs. It focuses on making connections quicker and cheaper in long-distance scenarios on wafers.
  2. Photonic wafer-scale integration offers benefits like reduced energy use and lower latency compared to traditional electrical methods, but the right network setup has been a challenge. Finding a suitable layout is important for maximizing performance.
  3. The HyperX design has advantages like fewer layers and a straightforward layout, which can help minimize complications in building these systems. It's a simple yet effective way to boost the performance of interconnects in photonic setups.

The Devil and the Cerulean Sweater

Maximum Effort, Minimum Reward • 127 implied HN points • 21 Oct 23
🔬 Science Optics
  1. The color cerulean comes from the Latin word for sky and should represent the color of the sky.
  2. Rayleigh scattering explains why the sky appears blue - shorter wavelengths scatter more.
  3. Calculating the color of Anne Hathaway's cerulean sweater using physics resulted in a color close to the original, proving Meryl Streep's character in 'The Devil Wears Prada' was correct.

NextSeq 550 Flowcell Notes

ASeq Newsletter • 14 implied HN points • 29 Feb 24
🔬 Science Optics
  1. NextSeq 550 flowcell has a unique design where the gasket sits on the flowcell interface and the glass is thicker than other instruments, possibly for stability.
  2. The flowcell glass thickness is surprising and might impact the imaging process, requiring specific optics designed for it.
  3. The material of the channel spacer in the flowcell is unknown, leading to curiosity about its composition and potential patent research.

Superb Halos

GOOD INTERNET • 13 implied HN points • 17 Jan 24
🔬 Science Optics
  1. Atmospheric ice crystal optics can create superb halos that are visually stunning and fascinating.
  2. Halos are optical phenomena caused by ice crystals in the atmosphere, with different types like the 22° Halo.
  3. Kenneth Libbrecht, known as the "pope of snow crystals," released a monograph explaining the formation of ice crystals and snowflakes.

7x50 Binoculars Are the Best

Kartick’s Blog • 0 implied HN points • 22 Feb 26
🏝 Travel Optics
  1. 7x50 binoculars give the best balance of steady magnification and a large exit pupil, so they’re bright, easy to align with your eye, and comfortable for detailed viewing day and night.
  2. Higher magnification and smaller objectives (like 10x42) amplify hand shake and produce a smaller, darker exit pupil, so they often don’t show more detail and cause more eyestrain; zooms also perform worse and good image-stabilized models are very expensive.
  3. Big tripod-mounted bins (like 20x80) can give more magnification but are heavy, need a very stable tripod and a seat, and are less portable, so they’re best kept as a second pair while 7x50s remain the mainstay.