Table 6.6 summarizes Japan's strengths compared to those of the United States in the twelve optical sensor technology fields discussed in this chapter. The table compares R&D activities as well as commercial or application activities, and looks at both current and future work.

Table 6.6
Optical Sensor Technology Status, Japan Compared to the United States

Research and Development of Optical Sensor Technologies

The JTEC panel's assessment is that Japan lags the United States in all areas of current R&D. As already noted in Table 6.5, virtually all state-of-the-art results have been generated by U.S. laboratories. U.S. government laboratories, in particular NRL and NIST, have played a seminal role in establishing U.S. technological leadership in the optical sensors field. Several university programs, such as that of the University of Virginia, have also made significant contributions.

The panel also concludes that the trend is for the United States to lead Japan in most optical sensor R&D categories in the near future, with the exception of the electric and magnetic sensing area, where publications activity indicates increasing activity in Japan and a neutral position relative to the United States. The R&D trend for the pressure, displacement, vibration, and flow sensors is rated neutral simply because activity levels are so small that no conclusion is possible.

Applications of Optical Sensor Technologies

Enabling science and components

In the applications and commercial aspects of optical sensor technology, the JTEC panel finds the picture to be more mixed. It seems that Japan is ahead in the area of enabling science and components. Optical sensor technology was built on the foundation of fiber communications components and technologies. As noted in other chapters (see especially Chapters 4 and 5), Japan's activity in optical packaging and many optoelectronic enabling components is ahead of the United States. The semiconductor lasers used in many sensor devices come from Japanese companies. The electronic packaging and connector technology of companies such as Kyocera, Sumitomo, Fujikura, and Furukawa will be very valuable to optical sensor development and commercialization efforts. Work is increasing in the United States, however, and the trend over time will likely be toward neutrality.

Networks and instrumentation

The relative status of Japan and the United States in networks and instrumentation appears neutral. Japanese companies have already deployed distributed temperature sensors. Certainly network technology of optical fiber communications is an area where the two countries compete quite evenly, and networking with optical sensors will be increasingly common. It is expected that parity will continue.


The United States is ahead in the chemical sensor application area. Several U.S. companies are selling units to measure various gases. For example, First Alert's carbon monoxide monitor, which uses optical techniques, sells many thousand units a year. The trend is expected to continue in favor of the United States because of U.S. environmental and safety concerns.


There are two ratings for temperature sensor applications: parity exists in the area of point sensors (the number of applications is small); however, for distributed sensors, Japanese companies have the lead in deployment, and their relative position is likely to become stronger over time, since there is little U.S. activity in this field.


In the area of strain sensing, the United States is ahead. Babcock & Wilcox is selling microbend sensors. Currently there appears to be no Japanese commercial presence. The trend is expected to continue.


The United States is ahead in the biomedical area. Camino Laboratories is thought to be selling about 60,000 units a year to perform cranial pressure sensing. The 3M subsidiary, CDI, is reported to be selling per month on the order of 10,000 blood gas analyzers that use optical sensing technology. The trend should continue in favor of the United States, since little activity is noted among Japanese companies.

Electric and Magnetic

Japanese companies are probably ahead in the area of electric and magnetic field sensing. Deployment of current and voltage sensors has already taken place in Japan and Europe. The trend is expected to continue in favor of Japanese companies.


For rotation sensors, at least of the intermediate grade, the Japanese are clearly ahead. As noted above, Hitachi is capable of producing 5,000 units a month and is selling to automobile manufacturers. The United States has in place programs to provide cost reduction and scale-up. The trend is expected to be neutral, provided automotive FOGs do not become incorporated in a broader cross-section of vehicles. This will be interesting to watch over the next few years.

Other sensors

For pressure, displacement, vibration, and flow sensing, relatively little activity is occurring; nevertheless the United States appears to lead in all these areas, with the possible exception of vibration. In that area, it is rumored that Japanese companies are selling an optical microphone. If so, the trend is expected to continue in favor of Japan. In the other areas, the trend is likely to be neutral.

In sum, the JTEC panel's assessment is that the United States leads in virtually all high-performance optical sensing work. This has occurred due to the strong effort of the national and Defense Department laboratories, notably NRL and NIST, together with DoD-funded work at several leading universities. The United States also leads in start-up companies in the optical sensor field. Several of these have been purchased by non-U.S. companies over the last few years; e.g., Metricor by Photonetics and the Westinghouse effort by ABB. It appears that Japanese companies active in this field are focusing on high-volume applications with perhaps lower performance requirements. This is certainly true for Hitachi's fiber-optic gyroscope and may also be true for distributed temperature and voltage sensors.

Published: February 1996; WTEC Hyper-Librarian