The detection, precise location, specific identification, and tracking of targets and an accurate battlefield damage assessment are key elements of the JWCOs of Information Superiority, Precision Force, Combat Identification, Joint Theater Missile Defense, Military Operations in Urban Terrain, Electronic Combat, and Counter Weapons of Mass Destruction. EO offers advanced technology solutions to the problems of high-resolution target location and identification, nighttime surveillance, and high-capacity data storage and processing. In addition, electro-optics is the basic technology of displays, which are crucial to all man-in-the-loop systems. The continued development of high-performance, man-in-the-loop, and autonomous systems using advanced EO technology will substantially advance global surveillance and communications; all-weather, day/night, camouflage-resistant precision strike missions against fixed and mobile targets; advanced antisubmarine warfare capabilities; and space and sea control systems.
3.7.2.1 Goals and Timeframes. High-performance sensors, displays, and data storage and processing will be required to meet future warfighter needs. Photonics will provide high-capacity, rapid-access data storage; distortionless wideband analog fiber optic communications for sensor, emitter, and antenna remoting; ultra high speed data processing for real-time analysis of SIGINT and ELINT data; and new approaches to steering and control of microwave beams. Display technology will address the problems of developing high-definition, helmet-mounted displays for the individual soldier and the aircraft pilot. A short-term goal is to demonstrate the capability of the active matrix electroluminescent display (AMEL) to operate with analog inputs for low power and compatibility with existing signal sources. Cost reductions in IRFPAs will be sought through uncooled sensor technology and by improvements in the functionality of cooled IRFPA technology. New applications will be addressed through development of multispectral sensors. Laser technology will attempt to lower the cost per watt of semiconductor lasers, develop long-lived blue laser diodes, and demonstrate eye-safe tunable monomode optical fiber lasers. Specific goals are listed in Table VII-8. Long-term (FY01-FY05) goals include integration of IRFPA and ATR functions, 3D stereoscopic displays, and monolithic optoelectronic integration leading to 2D optical "smart" pixel arrays for high-speed parallel processors.
| Fiscal Year | Goals |
|---|---|
| FY97 | Demonstrate thin-film ferroelectric FPA with NEDT of 0.05 K. Demonstrate integrated high-resolution, 60-deg FOV, low-power helmet-mounted sensor. Develop thermally compensated, high-resolution strain sensor for HASS. |
| FY98 | Demonstrate 3D WORM optical memory system. Demostrate 2-18-GHz optical interconnect for airborne RF signal distribution. Design composite hull fiber optic sensor system for Fast Patrol Boat (FPB). Demonstrate long-lived (>100 hours) room-temperature blue laser. |
| FY99 | Demonstrate parallel optical interconnects to 2.5 Gbytes/s. Demonstrate 1-100-GHz optical RF frequency synthesizer for EW, ELINT, and ECM. Demonstrate 0.01° NEDT uncooled FPA with 30-micron pixels. Build FPB fiber optic sensor system and conduct sea trials. Demonstrate eye-safe (1.5-1.6 mm) 3-W monomode fiber laser. |
| FY00 | Demonstrate 1-100-GHz channelizer for ELINT/SIGINT. Demonstrate capability of 3D read-write-erase optical memory. Demonstrate full-color, high-resolution (>1,000 lines) "smart" display. |
3.7.2.2 Major Technical Challenges. Key challenges in the laser diode array area include extending the range of available wavelengths in the MWIR and LWIR bands and reducing size, weight, power consumption, and cost. A cost target of $1 per peak watt is sought. In focal plane arrays, the key short-term challenges are in improving sensitivity and reducing cost through functionally improved and new uncooled sensor technology. Longer term, multispectral cooled FPAs will address the problem of detecting dim and camouflaged targets automatically in ground clutter.
The enormous potential of photonics technology for high-speed data transmission and processing is being exploited for peculiarly military applications. The key technical challenges are in extending the capability of optical recording and data storage to provide increased capacity and faster retrieval to allow processing of SIGINT and ELINT data in real time, using the vast bandwidth of optical waveguides for microwave transition on optical fiber, which allows sensor remoting in SATCOM and ECM applications and developing high-speed, 2D parallel processors for a range of applications including antijammer beam-null steering. Fiber optic sensors are needed for hydrophones and strain-sensing in composites and pose challenges in components, sensor array fabrication, multiplexing, and signal processing. The key challenge in displays for military applications is the development of the helmet-mounted display where low-power consumption, low weight, and high resolution are the principal requirements. Long-term needs are focused on a full-color, high-resolution display with integrated drive electronics.
3.7.2.3 Related Federal and Private Sector Efforts. There are significant commercial activities in flat-panel displays, optical recording, and fiber optics for telecommunications and local broadband services. There is also work at various federal laboratories where development of fiber optic subsystems for specialized tasks such as nuclear test instrumentation have typically been addressed. The DoD-funded efforts use COTS technology wherever possible, supplemented by research and development of the technology and components needed for military applications. A typical example of this approach in the photonics area is the use of COTS optical fiber technology combined with government-sponsored development of the advanced laser sources and detectors needed for military requirements for high-speed analog communications.
The EO technology subarea is organized in four major thrusts.
Compact Solid-State Lasers. The goals are to meet future laser requirements for infrared countermeasures against IR-guided missiles; design multifunction lasers for ranging, designation, IFF, and laser radar functions; and develop electrically driven, high-energy lasers for sensor and platform destruction that require lasers well beyond the extrapolated state of the art of flashlamp-pumped or diode-pumped solid-state lasers. Each application area has implicit wavelength requirements that generally reduce performance of current lasers by factors of three or more. Also, laser packaging for field use has been a long, expensive process. This thrust is aimed at developing the essential elements of laser technologies that offer the potential of order-of-magnitude or greater performance improvements with intrinsic advantages in wavelength control and packaging. Specific needs for this technology are referenced in the JWCOs of Electronic Combat (for IRCM, e.g., affordable, compact laser, minimum 2-W/20-kHz, mid IR) and Military Operations in Urban Terrain (for laser ranging). This thrust also addresses MOUT needs for laser illuminators and target designators not explicitly referenced.
Two technologies recommend themselves as having the potential of substantial improvements in performance. For the lower power missions, direct laser diode operation at the wavelengths of interest in the visible through the MWIR bands now appears possible. For higher power applications, the use of arrays of fiber lasers appearsto be an attractive candidate. This thrust is aimed either at validating the promise of these technologies or of finding even more attractive systems. The emphasis is on demonstrating device performance characteristics of an acceptable nature in power and lifetime, demonstrating the power scaling of the technology, and deriving system concepts for stressing missions.
Focal Plane Arrays. The FPA thrust focuses on the development of military-unique electro-optical devices and components for optical sensing and the integration thereof into sensor systems. The goals of this thrust are to provide faster, more accurate detection and targeting capabilities combined with the benefits of low weight and low power. Specific objectives include:
Displays. This thrust addresses an extremely wide range of system requirements. At one extreme, there is the miniature, low-power, low-weight, flat-panel devices for cockpit and individual soldier applications. This part of the thrust builds on the effort by DARPA to develop miniature digital displays. State-of-the-art optics (diffractive, aspherics, hybrids, etc.), sensors (CCD, intensified CCD), and flat-panel displays (AMEL, FED, FLCD, etc.) will be investigated and selected for future helmet-mounted, high-resolution display/sensor systems. Concurrent development of sensor readouts and display driver electronic architectures will be used to optimize power and bandwidth. In the longer term, all solid-state sensor and display systems with digital input/output imagery and symbology will be developed to integrate the individual soldiers and aviators into the digital battlefield. At the other extreme of this thrust are large, high-definition color displays for use by battlefield commanders for multimode C3 information and battle briefing. More advanced technical investigations address 3D image presentation for applications where depth perception is a critical requirement for understanding the information presented. Explicit references to display technology needs in the JWSTP are scarce; however, there are requirements for compact, low-weight and -power, high-resolution displays for such applications as the Helmet-Mounted Sensory Ensemble (DTO HS.12.02), and it is mentioned as a key technology in the JWSTP chapters on Information Superiority and MOUT. Large, high-definition displays are also an implied requirement for such applications as the Rapid Battlefield Visualization ACTD (DTO A.06).
Photonics. Photonics technology uses light for the transmission and processing of information and offers the potential advantages over conventional electronics of vastly enhanced data throughput and information capacity. From the military viewpoint, photonics provides both enhancements in existing systems, some of which are already close to being available in the inventory, and entirely new applications in areas such as high-speed processing, communications, surveillance antenna and receiver systems, automatic target recognition, electronic warfare, signals intelligence systems, and high-speed communications networks that are well beyond the capability of conventional electronics. These enhancements are necessary in order to achieve future requirements for enhanced system performance within the size, weight, power consumption, and volume constraints imposed by military platforms.
The thrust is organized into five divisions: optical memory and storage, optical processing and interconnects, photonics for antennas and radio systems, fiber optics sensors, and high-speed communications networks. This effort includes the development of devices and subsystems to demonstrate and quantify military system impact. This work is funded by the services, DARPA, and BMDO. There are numerous explicit references to photonics technology needs in the JWSTP and other needs that are implicitly addressed by emerging photonics technology, for example in ATR and tracking. The relevant JWCOs are Information Superiority (mass storage of information, tailored search and retrieval of information, automatic target recognition, rapidly deployable tactical fiber extensions, etc.); Precision Force (EFOG sensor system, multisensor ATR); Combat Identification (secure datalinks); Joint Theater Missile Defense (lasercom, high-speed optical datalinks, target discrimination algorithms); Military Operations in Urban Terrain (high-bandwidth datalinks, ATR, lightweight optoelectronics); Joint Readiness and Logistics (secure, high-rate, high-bandwidth communications); Joint Countermine (ATR); Electronic Combat (wideband datalinking); and Chemical/Biological Warfare Defense and Protection (remotely employable technologies, embedded monitors).
3.7.3.1 Technology Demonstrations. A number of ATDs have been approved in the photonics thrust. The Air Force has two ATDs in optical memory: High-Capacity Jukebox (AF/ACC, FY98) and 3D Memory (AF/AIA/AETC, FY01). In the area of fiber optics, two Air Force ATDs have been approved: Analog RF and Millimeter-Wave Optical Signal Distribution (AF/AIA, FY01) and Optical Control of Phased Arrays for Multimode Communications (AF/C4A, FY01). In the optical signal processing area, one Air Force ATD is the Integrated C3I Optical Processor (AF/ACC, FY01). The Navy has four ongoing fiber optic ATDs: Advanced Autonomous Decoy (N/PEO(TAD), FY95-97); Advanced ECM Transmitter for Ship Self-Defense (N/PEO(TAD), FY96-98); Precision Strike Navigator (N/ONR, FY96-98); and Multifucntion Electromagnetic Radiating System (N/NSPAWAR, PMW176 & SEA03K2, FY97-99). In the FPA thrust, the Army has a single ATD: Multifunction Staring Sensor Suite.
3.7.3.2 Technology Development.
Advanced Focal Plane Array Technology (SE.33.01). This DTO includes both cooled and uncooled arrays. The cooled technology focuses on dual-band and multispectral sensing for detecting dim and camouflaged targets in background clutter. The uncooled technology development aims for improved sensitivity and resolution while maintaining low cost, weight, and power consumption. The integration of IR and low-light-level FPA imaging in a single package will improve nighttime rifle sight effectiveness and allow the development of low-cost missile seekers.
Optical Processing and Memory (SE.35.01). This DTO addresses the problems associated with development of a 3D write once-read many (WORM) times optical memory for high-capacity data storage needs, advanced 3D read-write-erase memory, high-speed parallel guided-wave and free-space optical interconnects, and a one trillion operations per second optoelectronic processor demonstration. High-speed signal processing and information storage for C4I is driven by such operational realities as increasing jammer densities and the new requirements for low-observable surveillance and manipulation of large intelligence databases in real time. The processing requirements for many of these functions cannot be met conventionally. Hybrid or all-optical techniques offer a realistic solution to this processing dilemma.
Photonics for Control and Processing of RF Signals (EW, radar, and communications) (SE.36.01). This DTO exploits the huge bandwidth of monomode optical fiber to replace bulky, lossy, narrowband, and dispersive RF cable and waveguide. Optical fiber delay lines provide unprecedented bandwidth, which suggests their use as true time-delay elements in a microwave-phased array. Further, high-quality optical sources allow the novel implementation of RF systems on optical carriers with their attendant reduction in size (e.g., RF filters, channelizers, up/down converters). These applications are being developed. Multigigahertz analog fiber optic interconnects are being developed for high-fidelity remoting of antennas over kilometer distances. Full-scale optically controlled phased arrays for SATCOM and ECM applications are planned for FY00. A major aspect of these efforts is the development of components such as millimeterwave modulators, detectors, and semiconductor laser optical sources.
3.7.3.3 Basic Research. Research is an important component of the EO effort where much of the technology is emerging. Key basic research is being done in electronic and optical materials. The extensive work on GaN for blue lasers is a good example. Many photonics applications are component limited; consequently, there are significant research efforts for development of devices and components including guided-wave modulators; semiconductor lasers, switches, and spatial light modulators; and smart pixel arrays. In addition, research is being directed toward new nonlinear optical materials and techniques. The long-term goal of research in this area is monolithic integration of optics and electronics.
