Ralph A. Rotolante
In just a few years, the infrared (IR) detector marketplace has undergone vast changes resulting from mergers among major companies and technology advances that have produced an explosion of new applications. In 1991, the US commercial market for detectors was about $50 million (see Laser Focus World, Nov. 1991, p. 87 and p. 93). The big news was the emergence of platinum silicon (PtSi) technology. The military market, with eight major detector companies, was about $500 million and declining. Second-generation focal-plane arrays were just entering production.
Today, the commercial market for IR detectors is about the same in dollar value, but unit shipments have doubled. Demand for PtSi technology is declining in favor of uncooled detectors. On the military side, there are now only four major focal-plane-array suppliers (and several good smaller companies). The market hovers near $300 million, but should increase with the second-generation systems entering operational production.
Major detector types
Mercury cadmium telluride (MCT). This type of detector (with wavelength cut-off tunable from 2 to 15 µm) has been the military workhorse for about 20 years, starting with the US Army Common Module family of detectors (60, 120, and 180 elements). So far, more than 80,000 devices have been delivered worldwide.
The focal-plane-array material of choice for high-performance Army systems remains MCT, now in the form of 480 x 6-pixel second-generation units. One advantage is that the material can be tuned for peak sensitivity at various wavelengths during growth of the crystals. Thus MCT is the only detector type to have applications in all wavelength regions.
There is no single MCT technology. The crystals are grown in different ways and the photodiode detectors are fabricated and mounted (hybridized) to the silicon read-out integrated circuit by different techniques. Currently, Boeing North America (Anaheim, CA), DRS (Dallas, TX), Raytheon IR Center of Excellence (IRCOE; Goleta, CA), and Sofradir (Chatenay, Malabry, France) dominate this market. The largest company for MCT production is Sofradir, with about $25 million in detector sales in 1998.
Platinum silicon (PtSi). This material, with a wavelength cut-off of 4 µm, is the pioneer of staring sensors (two-dimensional arrays with no scanning necessary). Despite a very low quantum efficiency, the arrays were producible before the others so they now have a strong niche in the commercial predictive- and preventive-maintenance markets.
By 1994, FLIR Systems International (FSI; Portland, OR), with its PtSi camera, first took market share from the once-dominant AGEMA (Secaucus, NJ), which counted too soon on uncooled technology. FSI then acquired it, as well as the Inframetrics product lines.
The major PtSi detector suppliers are Mitsubishi and Nikon in Japan, Eastman Kodak (Rochester, NY), and Boeing North America (a late entrant). Infrared Components Corp. (Utica, NY) packages most US-made detectors in Dewars. But PtSi has passed its zenith and is being squeezed out of the staring markets by uncooled devices from the low end and InSb and MCT from the high end. PtSi is being phased out partly because of producibility issues. And the uncooled device works in the long-wavelength IR (LWIR) region, which offers advantages in many applications. Because of product "cannibalization"--uncooled replacing PtSi--and dropping detector prices, the total detector dollar market for commercial applications has been static, while the equipment market has grown.
Indium antimony (InSb). With a wavelength cut-off of 5.5 µm this technology has dominated the high-performance staring applications, mainly military. The primary suppliers include Raytheon (Dallas, TX), Lockheed Martin Santa Barbara Focal Plane (Santa Barbara, CA), and Cincinnati Electronics (Mason, OH). This high-quantum-efficiency device has been successful, even in large formats (640 x 480 pixels). Format sizes up to 2048 x 2048 pixels are now being developed.
Indium gallium arsenide (InGaAs). These devices exhibit a wavelength cut-off of 1.7 to 2.6 µm and are available in 2-in. wafers from several suppliers. The standard structure--In0.53Ga0.47 As/InP--is used for imaging between 1.0 to 1.7 µm. A graded layer technique with reduced indium content allows cutoff out to 2.6 µm. Arrays and cameras are supplied by Sensors Unlimited (Princeton, NJ). Niche applications include ice detection and silicon wafer inspection.
Uncooled imaging systems. These devices (with broadband-wavelength cut-off typically at 12 µm) use ferroelectrics from Raytheon, thermoelectrics from Infrared Solutions (Minneapolis, MN), and microbolometers from Raytheon, Boeing North America, and Lockheed Martin Infrared Imaging Systems (note: all microbolometers in the USA are licensed from Honeywell).
By far the biggest success has been with the Raytheon ferroelectric type of microbolometer, which has sold four times more than the other types. These units operate as driver's aids for army vehicles and as police patrol night sights. After several false starts, microbolometer production is just now ramping up. To date these devices are replacing PtSi cameras and remain as costly.
The key players
The big four focal-plane-array suppliers are now Boeing North America, DRS, Raytheon IR Center of Excellence, and Sofradir.
Boeing North America. When Boeing bought Rockwell International's detector group, it did not acquire the Rockwell Science Center (Thousand Oaks, CA), where the MCT detector material is grown. Focal-plane-array activity is now split between two companies. Likewise, the silicon read-out integrated-circuit supplier remained with the Rockwell entity. With Boeing's acquisition of McDonnell Douglas (infrared systems), though, the fractured focal-plane-array activity became vertically integrated. The aerospace manufacturer is strong in two areas--detectors for space applications, MCT, and others and in uncooled microbolometer focal-plane arrays. The firm also supplies PtSi focal-plane arrays.
Boeing and Indigo Systems (Santa Barbara, CA) recently teamed to develop an uncooled IR camera that weighs just 90 grams, operates on less than 600 mW of power, and is about the size of a D-cell battery. With funding from the US Army Communications-Electronics Command, both companies will introduce products for military and commercial applications.
DRS. This firm acquired the Texas Instruments (TI; Dallas, TX) focal-plane-array group. The deal included the California-based IR systems group. DRS is an important supplier to the US Army for the SADA II technology at 480 x 6-pixel LWIR and for the Javelin missile acquisition sight at 240 x 2-pixel LWIR. The company also recently demonstrated a 640 x 480-pixel LWIR.
Raytheon. When Raytheon bought TI and Hughes, the company found it had a Texas-based MCT detector business and an IR systems group. In California, it also had a detector and an IR systems business. When the US government forced Raytheon to divest itself of this duplicate capability, the company kept the Texas IR systems business and the California detector business. Now, former arch rivals TI systems and Hughes detectors work together.
Raytheon, which remains the world's largest detector supplier, absorbed Amber Co. and has consolidated by closing Amber's Goleta, CA, site. With the Amber acquisition, Raytheon now has a complete line of detector products, including MCT, InSb, lead selenide (PbSe), PtSi, and uncooled microbolometers. The Raytheon (TI) ferroelectric uncooled products are built in Texas.
The group delivers two key detectors for the US Army--the SADA II with 480 x 4-pixel LWIR and the army's shoulder-launched Javelin antitank missile with 64 x 64-pixel LWIR. It also supplies 640 x 480-pixel InSb systems for the V-22 and for the F-18. The advanced medium-range air-to-air missile seeker and other equipment will use its InSb 128 x 128-pixel staring focal-plane array.
Sofradir. This firm is unique among the big four in that it has not been divested, acquired, or merged. The company continues its steady market growth of 10%-15% per year, and MCT remains its only product to date, although the company plans to sell uncooled and QWIP (quantum-well IR photodetector) products next year. The firm has delivered more than 3000 units of the 288/240 x 4-pixel LWIR and ships more than 150 units per month of scanning and staring focal-plane arrays.
Sofradir is entering production on a 320 x 240-pixel MWIR unit that it claims will challenge InSb in the areas of uniformity, resolution, crosstalk, antiblooming, and temperature of operation. Sofradir is also entering production for the important SADA II US Army standard detector-Dewar (480 x 6-pixel LWIR).
The future looks bright for the IR detector marketplace. After a long gap between first- and second-generation systems, military applications are again entering production. The production numbers (tens of thousands) that the corporate market forecasters have been predicting for 15 years are finally arriving. This is true in Europe as well as in the USA for new missile programs and new FLIRs, such as the hand-held LWIR Sofie from Thomson-CSF (Paris, France).
The commercial market is exploding with new, important applications. Still, both military and commercial markets remain inhibited by producibility issues at the detector level. Once these issues are resolved, the markets will accelerate even more. It is difficult to quantify market growth in these circumstances because new applications are delayed where current needs go unfulfilled. At a minimum, based upon company backlogs and government plans, deliveries of IR equipment should increase by 30% per year over the next three years.
One of the biggest items to watch for in the future is a low-cost IR camera. Once the $2000 barrier is broken, a totally new market will emerge in commercial surveillance and robotics, perhaps as soon as next year.
RALPH A. ROTOLANTE is the principal of Vicon Infrared, a consulting firm in Acton, MA, and a member of the Editorial Advisory Board of Laser Focus World; e-mail: email@example.com.
Editor's note: All estimates of market size are those of the author.