Sandia National Laboratories has developed a new riflescope that can rapidly switch between magnification at the touch of a button, without changing the grip on the weapon or losing sight picture.
Called rapid adaptive zoom for assault rifles (RAZAR), the riflescope prototype has been developed by a Sandia optical engineer and former US Army Special Forces member optical engineer Brett Bagwell, to address the US military requirements.
Bagwell said: "The impetus behind the idea of push-button zoom is you can acquire what you're interested in at low magnification and, without getting lost, zoom in for more clarity."
RAZAR can zoom in milliseconds and perform 10,000 actuations on two AA batteries, and is also capable of enabling target engagement at diverse ranges and offers several distinct advantages, including speed and high resolution at varying distances.
Manufactured since 2006, the RAZAR prototype uses a patented active optical zoom system, called adaptive zoom, which was invented by another Sandia optical engineer, David Wick.
Wick said the adaptive zoom changes the focal lengths of two or more lenses by varying the curvature of their surfaces to provide optical zoom without changing their overall positions relative to one another. This enables the user to view either a wide-angle image or zoom in on an area of interest with a compact, low-power system.
In contrast, legacy optical zoom changes magnification by adjusting the positions of the lenses along the optical axis.
Using adaptive zoom, the Sandia team worked for 18 months to perfect the manufacturing process of the lenses, ensuring that the quality of the prototype could be replicated.
Adaptive zoom is supported by three core technologies, including a polymer lens core comprising two flexible, hermetically sealed membranes, and a Dynamic Structures and Materials-designed piezoelectric ultrasonic piezo motor to actuate the flex in the lenses.
In addition, variable-focal length system design tools were developed, including analytical expressions and computer models, which trace rays of light through optical systems.
According to Bagwell, the team conducted shock, vibration and temperature testing from 2010 to 2012, to ensure that the riflescope would prove to be reliable in the theatre.
RAZAR demonstrations to the US military began in 2010, while representatives from US Special Operations Command tested the riflescope at the Camp Atterbury Joint Maneuver Training Center near Indiana in 2012.
Former Special Operations Research Support Element sergeant first class Michael Squire said the ability to zoom between near and far targets within seconds, without having to take hands off the weapon, is 'game-changing'.
"The difference that can make, especially with somebody shooting back, could mean life or death," Squire said.
In addition to military riflescopes, RAZAR is also being considered for other applications, including medical imaging, binoculars for the entire range of users from military to birdwatchers, hunter scopes and mobile phone cameras.
Image: A US Army Special Forces member demonstrates the rapid adaptive zoom prototype. Photo: courtesy of Sandia National Laboratories.