The Power of SWIR Imaging: See the Light

Welcome to 1000 Tech Drive, your go-to podcast for all things optics and surveillance technology! In this episode, we uncover the exciting world of Shortwave Infrared (SWIR) imaging through Computar's ViSWIR Lens Series.

Discover how SWIR technology enables us to see through fog, inspect microchips, and enhance recycling processes. We'll break down the fundamentals, highlight recent innovations like Sony's integrated sensors, and explore real-world applications that are transforming various industries.

Join us for an insightful discussion about the next generation of vision technology and how it's reshaping our understanding of the world!

Transcript

In this episode of 1000 Tech Drive we will explore SWIR imaging and the Computar ViSWIR Lenes Series. Imagine a world where you could peer right through thick fog. See a coastline miles away, or maybe inspect the tiny wires inside a microchip without actually touching it. Yeah, or what about sorting plastics like different types instantly? Almost perfectly. Exactly. Or finding, you know, hidden flaws deep inside food. It sounds like science fiction, doesn't it? It really does. Well, today we're actually diving deep into the reality behind that kind of vision. It's called shortwave infrared technology or a SWIR Short. It's this incredible way to see stuff way beyond what our own eyes can perceive. And we've gathered some really insightful sources from Computar. 

They're a big name in optical innovation. We've got technical docs, a recent webinar called Vision Beyond Limits. Lots to unpack. Right. They're definitely pushing the boundaries there. So our mission for this deep dive, pretty simple really cuts through the jargon. You know, we want you to walk away with a clear picture of what SWIR is, how it actually works, and why it's becoming such a, well, a game changer across so many industries opening doors that were frankly, just dreams before. You know, it's easy to think infrared just means seeing in the dark like night vision goggles, right? But SWIR is it's different. It lets us see through materials, things that look totally solid, opaque to us. SWIR can sometimes see right inside, revealing internal stuff. Or what something's made of things that are just invisible. Otherwise, that's the real aha moment with SWIR. 

Okay, so let's really nail down the basics then. What is shortwave infrared fundamentally. Okay. Fundamentally it's a specific chunk of the electromagnetic spectrum. Think of it like light, but with wavelengths longer than red light that we can see. SWIR typically operates in the range of, say, 1000 to 2500 nanometers, 1000 to 2500 nanometers. It's okay. It's part of the infrared family, but it's distinct. Exactly. Its properties are unique in that range. And while we're defining things, there are a few other terms that get thrown around. Sometimes it get confusing, like, uh, hyperspectral imaging? Ah, yeah. Hyperspectral is like, imagine taking a picture not just in red, green, blue, but in hundreds of very, very narrow color bands stacked together. Hundreds. Wow. Yeah. It gives you this incredibly detailed spectral signature for materials. Really good for identifying specific things. Okay. 

And multispectral. Is that similar? Sort of but simpler. Multispectral uses just a few specific bands, maybe 5 or 10, not hundreds. It's more about comparing features in those selected bands rather than getting a full signature. Right. And then there's near-infrared and IR that's closer to visible light. Yep. NIR is just beyond red, often used for basic night vision, some remote controls, that kind of thing. Different wavelengths, different capabilities than swore. And then you have longwave infrared. That's thermal imaging, right. Seeing heat exactly picks up heat radiation typically around 8 to 15 micrometers. Think police helicopters tracking someone by body heat. That's. SWIR doesn't really see heat like that. It sees reflected light, just like our eyes. But in that specific infrared band. Okay, that makes sense. Heat versus reflected light and understanding these differences, these sort of colors of invisible light is key because each band tells you something different for heat, SWIR for seeing through certain things, or identifying materials based on how they reflect that specific light. It's like having different specialized glasses. Like you said, each pair shows a hidden layer. 

Precisely. You choose the right tool, the right wavelength for the specific problem you're trying to solve. So okay, you can't just use your phone camera for this. How do you actually build a system to see in SWIR? What are the essential pieces? Right. It's definitely a system, not just one magic component. First, you obviously need SWIR cameras. These have special sensors typically made with indium gallium arsenide or injuries that are sensitive to those SWIR wavelengths. You can add sensors. Okay then. And this is crucial. You need the right lighting. This might seem counterintuitive for infrared, but SWIR often relies on reflected light. Without proper illumination in the SWIR spectrum, your image might just look like a dull black and white visible picture. Ah, so you need special SWIR lights? Often, yes. Could be narrowband LEDs tuned to specific SWIR wavelengths, or sometimes broader sources like quartz halogen lamps. The key is the type of light, the wavelength that interacts with the object to reveal those hidden properties SWIR can detect. It's not just about brightness. Interesting. So camera lighting. What else? You also need filters. Bandpass filters. Multipass filters. These help isolate the specific wavelengths you're interested in cutting out noise from other light sources. Very important for getting clean data. And then the lenses. You can't just use a standard camera lens. COMP- yo͞o  - tär lenses' materials and coatings those infrared wavelengths to pass through efficiently, without getting absorbed or reflected too much. So the lens design is critical to absolutely critical. The Computar  guys in that webinar called it probably the most important part. The optical design also has to minimize things like chromatic aberration, which is even trickier across such a wide range of wavelengths. Visible and SWIR. You need sharp focus everywhere. Okay, so specialized camera lighting, filters and lenses. Then I guess software comes into play. You bet. You need image processing software to take that raw data, analyze it, enhance it, and pull out the useful information and powerful computers and processors to run that software and handle all the data, especially in real time applications like sorting or inspection lines. It's the whole package working together. Got it. The whole ecosystem. Now, you mentioned pushing boundaries. There's been a pretty big breakthrough recently hasn't there, from Sony. Ah, yes. This is really exciting stuff. 

Sony's new IMX 992 and IMX 993 image sensors. Their high resolution. The 992 is 5.3 megapixels, the 993 is 3.2 megapixels, which is great for detail, but the really revolutionary part is their Sinar technology. It's quite technical, but basically they found a way to bond the compound semiconductor layer, the photodiode part that sees Suad directly to the silicon readout circuit, using this copper to copper bonding, copper to copper bonding. Sounds advanced. It is. Think of it like this. Super efficient, seamless connection. It allows them to make the top layers of the sensor much, much thinner. And because it's thinner, more light actually reaches that crucial InGaAs layer underneath. Better sensitivity. Okay. Thinner means more light gets in. But what's the big deal about that? The big deal. The game changer is that these sensors can now see across both the visible spectrum and the IR spectrum. We're talking 0.4 microns, which is blue light all the way out to 1.7 microns, well into SWIR with one camera, not two separate ones, one single camera. Before this, if you needed visible and suave views of something, you almost always need a two separate camera systems, two cameras, two lenses, more complex integration, more cost, more space. Wow. So no more dual camera setups needed for that. Exactly. This simplifies everything dramatically. Think about putting this capability into smaller devices drones, robots, handheld inspection tools. It makes advanced imaging so much more accessible and practical. It's a huge leap that is huge. And Computar they've developed lenses specifically for these new sensors. Right. The ViSWIR series, they have they've designed lenses optimized for this broad visible to SWIR range. And these specific Sony sensors, they offer a couple of tiers actually. Okay. What are the options. Well for top end performance there's the ViSWIR hyper APO series. APO means apochromatic. Basically, it corrects for color fringing across multiple wavelengths, including visible and SWIR. These lenses give you ultra high resolution, high light transmission and crucially, no focus shift. No focus shift. What does that mean, exactly? It means the focus stays sharp. Whether you're looking at the visible light image or the SWIR image, or anywhere in between, you don't have to refocus the lens when you switch between looking at different colors of light, even the invisible ones. That's incredibly important for getting accurate aligned data from both spectrums simultaneously.

They offer a wide range of focal lengths in the light series, two from five millimeters wide angle up to 50mm. And wasn't there also a huge zoom lens mentioned something for really long distances? Oh yeah, the ViSWIR reflex zoom. That thing's a beast. It's a super telephoto. It goes from 520 millimeter all the way to 1300 millimeter. Focal length 1300 millimetres. Yeah. Designed for smaller sensors like the 11.8in IMX 993. Perfect for long range surveillance, coastal monitoring, that kind of thing. I saw that demo video, too. The one showing the wind farm in Japan. Yes, that was amazing. Through all that haze. Right. The visible camera showed basically nothing, just gray soup but the Sua camera with that reflex zoom, crystal clear image of the wind turbines, like 20km away. It just slices through a haze and pollution. Wow. Okay, so specialized tool for specialized needs. Yeah, but it shows the power. All right. So we have the tech, the cameras, the lenses. Yeah. Let's talk impact. Where is SWIR actually being used today? What does this mean for, you know, practical applications okay. One of the biggest areas hugely important is semiconductor inspection microchips. Again silicon the main ingredient in chips. It turns out it's transparent to suoi light above about 1100 nanometers. So you can literally see through the silicon wafer. Exactly. Regular cameras CCD or CMOs. They only see the surface if there's a tiny particle or defect between bonded layers deep inside the waiver stack, they miss it. But a square camera with its InGaAs sensor can see right through the silicon and spot those internal killer defects. It's absolutely vital for quality control and chip manufacturing. You can also use it for things like checking alignment between layers or finding electrical faults through photoemission analysis. That's incredible. Finding flaws you couldn't see before. What else? Plastic sorting is another big one. Different types of plastic reflect SWIR light differently, so you can set up systems in recycling plants that instantly identify, say, PET bottles versus PVC containers and sort them automatically. Yep, they're reporting sorting efficiencies up to 98% in some plants using SWR. It's making recycling much more effective and economically viable. 98% wow okay. Chips. Plastics. What about food? Food inspection. Definitely. SWIR can be used to spot foreign objects, maybe bits of plastic or contaminants that X-rays might miss. It's also used for quality grading, like assessing the fat content or quality of meat. So it works alongside X-ray. Exactly. It's often a complementary technology. X-ray is good for dense objects like metal or bone. SWIR is better at seeing organic differences, moisture content, bruising under the skin of fruit, things like that adds another layer of safety and quality checks. Makes sense. And you mentioned surveillance earlier. Right. Surveillance and security because SWIR cuts through haze, fog and even some smoke much better than visible light. It's great for coastal monitoring, border security, airport perimeter checks. You can see targets much farther away and in conditions that would blind a normal camera better than thermal. Two. Sometimes in some ways, yes, especially during the day or with some ambient light, it provides more detail, like being able to identify what an object is. Not just that it's warm, but it does need some light. Reflected light at night with zero illumination. Long wave thermal imaging is still usually the go to for just detecting presence based on heat. So they both have their place day versus night. Detail versus heat detection. Got it. And these are just the established applications. Think about emerging areas agriculture monitoring crop health or moisture stress. Medical imaging potentially seeing deeper into tissues non-invasively. Clinical. Yeah. Or anti-counterfeiting analyzing artwork or historical documents without damaging them. Drug detection even potentially using SWIR lasers for communication through clouds or fog. The possibilities are a still unfolding. It really raises the question, what else could we see if we look with these different wavelengths? It really does. Yeah. So wrapping this up, it's pretty clear that shortwave infrared is this incredibly powerful tool. It lets us see the invisible, uncover details hidden from our eyes. And these new innovations, like Sony's sensors that combine, visible and swore in one package paired with advanced lenses like Computar's ViSWIR series, they're making this tech more integrated, cheaper, and just generally more accessible than ever. Absolutely. It's a fundamental shift, really, moving beyond the limitations of just visible light. It changes how we observe, how we measure, how we interact with the world. It opens up entirely new ways to solve problems, you know? Yeah, it makes you think how many other layers of information are out there all around us, completely invisible right now, not just in labs or factories, but maybe even in our everyday lives. What else could we understand if we just, uh, learned how to look with different eyes or different lenses or different lenses? Definitely something to think about.