Have you ever wondered if those night vision goggles in movies work? Can you really see in the dark? Well, the answer is yes—they do work, allowing you to see in the dark. This is made possible by night vision technology. But how does it work?
First, we must understand that the amount of energy in a light wave is related to its wavelength. If a wavelength is shorter, it has higher energy, and vice versa.
In visible light, red has the least energy, while violet has the most. Infrared light, on the other hand, involves near-infrared (near-IR) with wavelengths in the 0.7-1.3 microns range, mid-infrared (mid-IR) with wavelengths between 1.3 and 3 microns, and thermal-infrared (thermal-IR) with wavelength ranges from 3 microns to over 30 microns.
Unlike Near-IR and mid-IR, which are used by various electronic devices, thermal-IR is emitted by an object rather than reflected off it.
So, night vision technology enables vision in the dark by either amplifying available light or detecting infrared radiation. Night vision devices capture photons of light and amplify them to create a visible image or detect infrared radiation emitted by objects and convert it into a visible image.
Night vision equipment—including scopes, goggles, and cameras—is commonly used in military, surveillance, navigation, law enforcement, hunting, wildlife observation, hidden object detection, and security.
Driven by this growing demand across various applications and technological advancements, the market size of night vision devices is projected to grow from $8.68 bln in 2024 to $12.74 bln by 2029.
New Discovery: Paper-thin OLED for Compact, Lightweight NV
Amidst this, researchers from the University of Michigan have created a new type of OLED that is thinner than paper and can potentially replace bulky night vision goggles with lightweight glasses. This could make NV glasses cheaper and more practical for extended use.
Source: University of Michigan
Organic light-emitting diodes, or OLEDs, are among the most successful organic electronic devices and dominate the mobile display market. They are also expanding into automotive, wearable devices, and a broad range of lighting applications. Smartphone screens, such as those in the iPhone, use this type of light.
Against this backdrop, the study introduced a new class of organic light-emitting devices that display bistability due to positive photonic feedback between an organic photodiode and a tandem OLED integrated into the same layer stack.
Funded by DARPA, the research was made in collaboration with aerospace and defense contractor RTX and OLEDWorks, a company that manufactures OLED lighting products. OLEDWorks and Penn State University, where the study originated before its corresponding author, Chris Giebink moved to U-M., are currently working on patenting the technology.
Conventional night vision systems rely on image intensifiers to amplify the incoming light. The new OLED device also does that—converting near-IL into visible light and then amplifying it over 100x. However, the OLED device does it all without the high voltage, weight, and inconvenient vacuum layer needed in traditional image intensifiers. To achieve high amplification, the researchers instead focused on optimizing the device’s design.
According to Giebink, U-M professor of electrical and computer engineering and physics, a fascinating feature of the new approach is that the light is amplified within a thin film stack, less than a micron (0.001 mm) thick. This is far thinner than a single strand of hair, which has a thickness of about 50 microns.
By operating at a much lower voltage than a conventional image intensifier, the device reduces power consumption, which in turn extends battery life.
Technically speaking, the novel OLED device operates by combining a photon-absorbing layer with a stack of OLEDs with five layers. The photon-absorbing layer converts IL into electrons, while the OLED layer converts the electrons into visible light photons.
Ideally, five photons are generated for each electron that passes through the OLED stack. Some of these photons are emitted to the user’s eye, while others are reabsorbed back into the photon-absorbing layer.
This way, the system still generates more electrons that again move through the OLED, creating a positive feedback cycle that greatly enhances the amount of output light resulting from a given amount of input light.
While OLEDs in previous attempts have been able to convert near-infrared light to visible light, there has been no gain. This means we got only one output photon from one input photon. According to the study’s lead author, Raju Lampande, U-M postdoc research fellow in electrical and computer engineering:
“This marks the first demonstration of high photon gain in a thin film device.”
But this is not the end of this device’s capabilities. It actually showcases a memory behavior that can have applications even in computer vision systems. This behavior is called hysteresis, where light output at a given moment depends on the intensity and duration of past input illumination.
So, in an “unusual” move, the new OLED device remains on and remembers things over time. This is unlike the normal situation under which the upconversion OLED begins to output light when illuminated, only to stop doing that when illumination is turned off.
The device’s memory behavior presents some challenges for NV applications, but it may create an opportunity for image processing that works more like the human visual system. In that system, biological neurons pass signals depending on the timing and strength of incoming signals.
The new OLED’s ability to remember past inputs could also make it useful for certain kinds of neuron-like connections. These connections enable an input image to be interpreted and classified without processing the data in a separate computing unit.
The OLED device was fabricated by the researchers using materials and methods already widely used in OLED manufacturing. As such, it has the potential for near-term use in new types of display and upconversion imaging applications, as well as offering a new platform for image recognition and neuromorphic optoelectronics.
Utilizing existing materials and processes already available can also significantly improve the cost-effectiveness and scalability of the technology for future applications.
Other Night Vision Innovations
Among the ongoing innovations happening in the space of NV, most recently, a team of engineers took inspiration from cats’ optic systems to develop a new type of camera that can capture images in the dark. The device is also able to see through camouflage, making it useful in far-ranging applications such as military drones.
So, a cat’s eyes glow in a dark room, which happens because the feline eye features tapetum lucidum, a structure that reflects light. The retina of the cat’s eye not only absorbs light hitting it directly but also that’s reflected by tapetum lucidum, thereby giving cats enhanced night vision.
This is not all. The eyes of house cats have yet another feature, a vertical pupil, common in ambush predators with small body sizes. What this vertical pupil does is it gives small felines enhanced depth perception. These pupils help them focus on their target while filtering out the clutter in the background.
So, to redevelop these structures, engineers from different South Korean universities, led by Young Min Song, a professor at the Gwangju Institute of Science and Technology, fabricated a vertical camera aperture. When combined with a silicon photodetector array having silver reflectors, it simulated the dual light absorption of the tapetum lucidum.
According to the new research, when tested by pointing at a concealed mouse-shaped object at various distances, the device successfully distinguished the shape in spite of the camouflage.
However, it’s not error-free. The man-made image sensor isn’t as acute as the one that cats naturally possess. The cat eye camera’s slit-like pupils mean it has a reduced field of vision. To overcome this limitation, the engineers propose devices using this camera to mimic the cat’s head and shoulder muscles for full cat movement duplication.
This isn’t the first time researchers have taken inspiration from nature. Biologically inspired technology is vastly popular and common. Even lenses have been created in this manner, utilizing the biology of cuttlefish, elephant nose fish, and mantis shrimp. Cat’s eyes, in particular, hold the promise for dark conditions and “potential for facilitating the deployment of mobile robots to a variety of unconventional robot applications by replacing humans” in surveillance robots, unmanned vehicles, and military drones, noted the study.
A few months ago, another teacher took a new all-optical approach to enhance infrared vision, revolutionizing night vision tech. For this, the Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems (TMOS) created an extremely thin infrared filter.
Being thinner than a piece of cling wrap, it can even sit on top of the eyewear, allowing the wearer to view both the infrared and visible light spectrum simultaneously. The new technology would reduce the weight of the technology substantially, to less than a gram.
With such benefits, the resulting technology can find significant opportunities in the biological imaging surveillance and autonomous navigation industries.
For the research, the team used upconversion technology based on metasurface to provide an easier pathway for processing light photons. Here, the photons travel through a resonant metasurface, mingling with a pump beam.
The use of non-local lithium niobate metasurface enhances photons’ energy and, instead of converting them to electrons first, pulls them into the visible light spectrum. This eliminates the need for cryogenic cooling, hence reducing the ‘noise’ for sharper images in conventional NV and, as a result, can put an end to the bulkiness of these goggles.
“This is the first demonstration of high-resolution up-conversion imaging from 1550-nm infrared to visible 550-nm light in a non-local metasurface.”
– Rocio Camacho Morales, the study author
Talking about the decision to go with these wavelengths, Camacho noted that the 1550 nm is usually used for telecommunications while human eyes are highly sensitive to the other one. In their future research, the team will expand the wavelength range the device is sensitive to with the aim of “obtaining broadband IR imaging, as well as exploring image processing, including edge detection.”
Companies Advancing the NV Technology
In the world of night vision technology, companies like L3Harris Technologies (NYSE: LHX), BAE Systems (OTC: BAESY), and Leonardo are helping take the space forward.
Among these, L3Harris is a major player in defense and aerospace, producing advanced night vision goggles and systems for military and law enforcement. BAE Systems also develops night vision and infrared imaging technologies for military applications, similar to Leonardo, whose night vision equipment—including image intensifiers and thermal imaging systems—serves the defense, security, and aerospace sectors.
Then there’s FLIR Systems, now part of Teledyne Technologies (NYSE: TDY), which produces thermal imaging and infrared cameras used in night vision systems across various sectors. Raytheon Technologies (NYSE: RTX) is particularly known for producing infrared and thermal imaging systems, which are essential for NV capabilities in the military and aviation sectors.
Now, let’s take a deeper look at the companies helping advance the tech:
#1. Kopin Corporation (NASDAQ: KOPN)
A key player in advancing night vision technology, Kopin specializes in developing microdisplays and wearable technologies, including heads-up displays (HUDs), which are crucial components of modern NV systems.
In May, the company secured a contract from an unidentified defense customer to develop a low-latency digital night vision system incorporating its OLED microdisplay technology. Analog NV goggles have been used in military operations for over two decades. By leveraging efficient digital sensors and advanced OLED microdisplays, the new project aims to enhance NV capabilities with a fully digital system. This integration also reduces the size and projection of night vision devices, improving their operational efficiency.
With a market cap of $74.23 million, the company’s shares are currently trading at $0.65, down 69.77% YTD. It has an EPS (TTM) of -0.40 and a P/E (TTM) of -1.53. For Q2 of 2024, Kopin reported $12.3 million in revenue, an increase of 18% from the same quarter last year. The company’s YoY product revenue jumped 84%, with revenue from defense products seeing an increase of $5.4mln and a $0.3mln increase in industrial product revenues. The cost of product revenues meanwhile came in at $8.7 million, which is 79% of net product revenues, down from 95% in 2Q23. During the quarter, the net loss was ($5.9) million or ($0.05) per share.
According to CEO Michael Murray:
“(Five new customers have placed development orders, providing) significant multi-million dollar per year production revenue opportunities in the future.”
He further shared that he was awarded the design, development, and production of the US Army’s Next Generation-Short Range Interceptor (NG-SRI) system, which will start in 2027. Other contracts involve researching optical approaches for Visual Augmentation Systems for the US Army and creating a way to reduce the size and weight of optics needed in advanced sensor systems for the US Navy.
#2. Elbit Systems (NASDAQ: ESLT)
This defense company is involved in developing advanced night vision goggles, thermal imaging systems, and other electro-optical systems for both military and civilian uses.
This month, Elbit Systems signed a $28mln contract with the US Army for additional helmet-mounted, AN/PVS-14 monocular night vision devices that allow soldiers to move rapidly at night. The device incorporates an infrared illuminator and high-magnification lenses to capture clear images in low-light conditions and as far as 150 meters. This deal comes on the back of a $12mln contract the company signed for supplying an undisclosed number of AN/PVS-14 devices to the army. Before this, in 2021 as well, the army and Elibit had a $54mln deal for the same devices.
With a market cap of $8.5 bln, the company’s shares are trading at $192.24, down 9.85% YTD. It has an EPS (TTM) of 5.44, a P/E (TTM) of 35.35, and a dividend yield of 1.04%. For Q2 of 2024, Elibit reported a revenue of $1.6 billion, GAAP net income of $78 million, Non-GAAP net income of $93 million, and an order backlog of $21.1 bln. Cash flow for the six months ending June 30, 2024, was $26.0 million, down from $210.7 million recorded at the end of the first half of last year due to an increase in inventories and trade receivables.
Talking about the company’s 12% YoY increase in revenues, its CEO Bezhalel (Butzi) Machlis said:
“The continuous high demand for our products and solutions reinforces our position as industry leaders.”
Conclusion
Night vision technology has grown exponentially in recent years, offering benefits like increased compactness, reduced power consumption, and improved image clarity. The development of thin OLED-based devices, cat-inspired cameras, and advanced metasurfaces highlights the importance of continued research to achieve even better results, which can expand the potential applications of night vision even further, including helping us gain a deeper understanding of the world around us.
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