By John Oncea, Editor
The use of night vision devices by the military first started in 1939. Numerous technological advances have been made since then, to the point we may soon see contact lenses provide the same advantages without the bulkiness of cumbersome headgear.
Photonics and defense have been best friends since day one. Photonics technologies have improved aircraft monitoring and maintenance – including heads-up displays and fiber optical networks – and provided higher-quality sensing and communications devices.
Photonic technologies are used for missile guidance and tracking, enable satellite missions for geostationary, medium-earth orbit (MEO), and low-earth orbit (LEO) space satellites, and photonics theory drives high energy lasers, such as the High Energy Laser with Integrated Optical-dazzler and Surveillance (HELIOS).
Photonics also play a crucial role in night vision technology, enabling military personnel to operate effectively in low-light or complete darkness. Night vision devices utilize photonic principles to detect and amplify available light, such as moonlight or starlight, to create a visible image. Photonics-based night vision technology has significantly enhanced the capabilities of military forces for surveillance, reconnaissance, navigation, and target acquisition during nighttime operations.
What We Know About Night Vision And The Military
Photonics is a foundational technology in developing night vision systems for defense. By harnessing the properties of light and using various optical and electronic components, photonics enables military forces to operate effectively in low-light conditions, enhancing their overall capabilities for reconnaissance, surveillance, navigation, and target engagement during nighttime operations. The following are just a few of the technologies used by the military that owe, in part, their existence to photonics.
- Light Detection: Photonics-based sensors, such as photomultiplier tubes (PMTs) and avalanche photodiodes (APDs), can detect individual photons of light. These sensors are highly sensitive and can detect even extremely low levels of light, including ambient light in the environment.
- Image Intensification: One of the critical technologies in night vision is image intensification. This process involves capturing incoming light through an objective lens, converting it into electrons using a photocathode, and then accelerating these electrons using a microchannel plate (MCP) or other electron multiplication technologies. The accelerated electrons strike a phosphor screen, converting the electrons back into visible light, which forms an intensified image. This process amplifies the available light, making it possible to see objects in very low-light conditions.
- Infrared Imaging: Photonics-based night vision devices often incorporate infrared (IR) sensors. IR light is not visible to the human eye, but it is emitted by warm objects and can be detected using specialized sensors. IR imaging allows military personnel to see objects and individuals that emit heat, such as vehicles, humans, and equipment, even in complete darkness.
- Thermal Imaging: Thermal imaging is a specific type of photonics-based technology that detects the heat emitted by objects. Thermal cameras create images based on temperature differences, allowing military operators to identify targets based on their thermal signatures. This technology is particularly useful for detecting camouflaged or hidden threats that might not be visible using traditional visible light or IR imaging.
- Laser Range Finding and Targeting: Photonics-based lasers can be integrated into night vision devices for laser range finding and target designation. These lasers emit pulses of light that bounce off a target and return to the device, allowing for accurate distance measurements and target identification, even in low-light conditions.
- Digital Imaging and Processing: Modern photonics-based night vision systems often incorporate digital imaging and processing technologies. This allows for the capture of images or videos, image enhancement through digital filters, and integration with other data sources for improved situational awareness.
- Integration with Other Technologies: Photonics-based night vision systems can be integrated with other defense technologies, such as GPS, communication systems, and augmented reality displays, to provide comprehensive and real-time information to military personnel during nighttime operations.
ENVG-B And IVAS
“The first military night vision devices were introduced by the German Army as early as 1939, and were used in World War II,” writes Scholarly Community Encyclopedia. “AEG started developing the first devices in 1935. In mid-1943, the Army began the first tests with infrared night-vision devices and telescopic rangefinders mounted on Panther tanks.”
Much has happened since then, including the development in 2021 of Enhanced Night Vision Goggle-Binocular (ENVG-B), “futuristic night-vision goggles that transform lurking in the dark into a video-game-like experience.” According to the Washington Post, “The product is part of a years-long push to modernize tools the military uses. The helmet-mounted device, loaded with thermal imaging and augmented reality capabilities, introduces technology found in smartphones and gaming systems to traditional night-vision hardware.”
Traditional night vision goggles work by “converting the photons gathered in low-light light settings into electrons that were amplified as they passed through a vacuum tube and eventually lit up a phosphor-coated screen that provided a brighter image of what the goggles were seeing,” writes 311 Institute. “The traditional green color of night vision technology was chosen because it was considered to be the easiest color to look at for prolonged periods in the dark. But the brightened images lacked contrast and were often very noisy, which made it difficult for a user to understand what they were seeing. For
ENVG-B has upgraded from green phosphor tubes to white ones, resulting in better contrast and brighter images. Additionally, the goggles have technological advancements such as a thermal imager, which can see through obstructions like dust and smoke, even in complete darkness or underground. Furthermore, augmented reality enhancements have been added to provide real-time edge detection, which can outline objects like fellow troops. These goggles can even wirelessly communicate with an electronic scope on a weapon, allowing soldiers to remotely aim at a target without risking physical exposure to a threat.
According to L3Harris, the provider of ENVG-B technologies, over 10,000 U.S. Army soldiers are currently armed with the night vision goggle technology.
IVAS goggles, designed to make soldiers more effective in close combat, combine night vision with augmented reality tools for training and missions. The goggles can project data, such as maps and enemy positions, into a soldier's field of view and are based on Microsoft’s HoloLens mixed reality device.
According to Popular Mechanics, the Army has spent the last three years working on the goggles and expects to spend around $21.9 billion on them over the next decade. “The U.S. Army thinks IVAS is the technological leap the infantry needs to fight in the 21st century. IVAS, built around Microsoft’s HoloLens augmented reality (AR) goggles, packs a lot of capability into a relatively compact set. IVAS includes a rugged heads-up display, cable, computer pack (known as the ‘puck,’ wearable battery, squad radio, and power charger.”
Similar to the display in a fighter jet, IVAS goggles project crucial information directly into a soldier's line of sight. With IVAS, soldiers can view the positions of their squad or platoon, designated pathways across the battlefield, enemy positions, and other pertinent data. Additionally, they can receive feeds from nearby night vision devices, including low-light and thermal sighting systems. Soldiers can even “see” through the walls of vehicles they are riding in by accessing cameras mounted on the vehicle's hull or view the feed from drones flying over the battlefield. IVAS also provides the ability to properly identify enemy forces at a distance, using night vision and Advanced Targeting & Lethality Aided System (ATLAS).
One More Thing
Have you ever considered how convenient it would be to use night vision without having to wear bulky goggles? The U.S. Army has and is tracking the University of Michigan College of Engineering’s creation of a super-thin infrared light sensor using graphene – an atom-thin material related to graphite – that could help develop contact lenses to provide superior vision during nighttime operations. This technology would eliminate the need for soldiers to wear cumbersome headgear.
“Although the development of the lens has quite a ways to go before it is ready for production, let alone mass production, the U.S. Army has already expressed interest in using this new type of technology on the battlefield,” writes Lens.com. “It’s believed that the Navy SEAL Team responsible for killing Osama Bin Laden in 2011 may have worn similar contact lenses during their mission. Other military applications include use in thermal imaging cameras, aircraft turrets, and missile detectors.”
Graphene, a form of carbon commonly used in No. 2 pencils, can make dark images appear brighter by absorbing light. It's been dubbed the “wonder material” of the future by the American Physical Society because it’s incredibly thin (a million times thinner than paper), stronger than diamond, and more conductive than copper.
Typically, graphene only absorbs 2.3% of light, which isn't enough to create a visible image. However, when two layers of graphene are paired with an insulator, the signal is amplified significantly. These sensors not only have the ability to detect visible and ultraviolet light, but they also can detect the full infrared spectrum.