Professor Golant accidentally invented a device capable of measuring a huge range of temperatures. It can be used virtually anywhere, from inside a nuclear reactor to outside a spaceship.

This year, the Intel Innovation Prize at the 2^nd Russian Innovation Competition held annually held by Expert Magazine went to some real physicists. The name of the winning project promised little of interest to me as a journalist: High-Temperature Bragg Lattice-based Fiber Sensors. How was I supposed to explain this to our readers? It sounded like some kind of esoteric theory … The project leader, Professor Konstantin Golant, Doctor of Physics and Mathematical Sciences and Head of the Plasma Chemical Technology Laboratory at the Research Center for Fiber Optics at the General Physics Institute of the Russian Academy of Sciences, looked like a classical physicist: thin with glasses and a gray beard and surrounded by mysterious devices. He looked like someone more interested into jotting down formulae than dealing with daily life.
It turned out that innovations of Professor Golant and his team are not so detached from life after all. The winning invention is nothing else but a thermometer. It’s no ordinary thermometer from a drugstore, but quite an interesting device capable of measuring temperatures ranging from -180 C to +900 C. Moreover, it can do so with strong electromagnetic and radiation interference (for example, inside a nuclear reactor). On the surface, the device is quite simple but in order to understand how it operates, we had to remember some of our fundamental physics.

An optical fiber is a quartz glass thread with a core. Due to the core, the quartz thread operates as a light guide. A light wave runs along the core reflecting from the interface with peripheral glass of fiber. Over the last several decades, the main task facing fiber producers has been to reduce losses in the core so that a wave can run along a fiber for as long a distance as possible. To a considerable degree, they have succeeded.
Usually, germanium – a rare and hence very expensive element – is used as a glass additive to make the core. The refraction index of quartz glass can also be increased by inserting cheap nitrogen in place of expensive germanium. Only one link was missing: it was unclear how to handle nitrogen during standard fiber-optic production. The nitrogen core in optical fiber or, rather, the technology for producing it formed the basis for Golant’s innovation group at the Research Center for Fiber Optics of the A.M. Prokhorov General Physics Institute.
Konstantin Golant decided to apply plasma chemical technology to fiber production. To this end, Golant and his colleagues began to build their own plant in 1991.
During construction and initial experiments, the project met with extensive skepticism. The technology itself, as well as the idea of using nitrogen, looked very unusual indeed. Skeptics had an extremely persuasive argument: not a single foreign company, not a single foreign university or a R&D lab, with all their excellently equipped laboratories, were conducting experiments in that direction.
In 1994, the team succeeded in producing the first “nitrogen” fiber with limited losses suitable for the telecommunication industry. 1995 turned out to be a major turning point for the scientists, as their results were presented at OFC ’95, the largest international conference on optical communications, and were published in the world’s leading scientific journals. The conference presentation and the publications not only highlighted the achievements of Golant’s team but also attracted funding. International corporations started placing orders. The demand for optical fiber, especially for telecommunications, was invariably growing at the time. Corning, the world’s largest producer of optical fiber, couldn’t believe at first that the Russian physicists had succeeded in making the long-awaited product. After testing it, they purchased the first 50 km of the nitrogen fiber from Golant.
Naturally, all the parameters of the new, unique fiber underwent testing. It turned out, for example, that under radiation it behaved far better than standard fibers. Also, using the new fiber in one experiment the scientists made an attempt to produce a sensor based on so-called Bragg lattices, periodic nanostructures that reflect light at a certain wavelength. When a wide spectrum of light runs along a fiber with such a lattice, almost all wavelengths will pass all through the guiding structure. Only the wavelengths meeting Bragg’s conditions will reflect from the lattice. Should the fiber be heated, the refraction index will change, and other wavelengths will start reflecting from the Bragg lattice.
By measuring which wavelength corresponds to which temperature, you can also create a reverse device able to determine the temperature of the location of the Bragg lattice by the length of reflected wave. Optical fiber with a Bragg lattice turns into a thermometer or, rather, a temperature sensor. The length of the wave reflected from the Bragg lattice will change not only when the fiber heats up but also with fluctuations in voltage and pressure. So, Golant’s team can make this type of sensor as well using the same fiber.
An educated reader might ask what is new in all this. Fiber sensors based on this principle have existed for many years now and can be purchased at any open-air market. But Golant’s laboratory has made the sensors from their own, nitrogen-alloyed fiber. The Bragg lattice remains intact in this fiber at temperatures as high as 1,000ºC, whereas in ordinary fibers it disappears at 300ºC! That is to say, using nitrogen-alloyed fiber, you can make absolutely unique sensors of very high (and very low) temperatures.

All the Plasma Chemical Technologies Laboratory’s inventions were patented. Articles were published both in Russian and foreign scientific journals. But the scientists had no plans to create any business based on the remarkable sensors. Konstantin Golant and his colleagues would have continued their basic science, their reports at symposia, and their research for Corning and other corporation if it hadn’t been for a young executive from Sony who came up to Golant at a micro-optics conference in Japan in 1999. This young man exclaimed with the kind of agitation only the Japanese are capable of, “You Russians are all the same! You walk all over money scattered right under your feet and don’t bother to pick it up!” After these words, the Russian professor reflected on commercializing his research.
Only an amazing twist of fate can explain the timely appearance at the Research Center for Fiber Optics of Yaroslav Gusev, a 27-year old businessman born at the Chernogolovka scientific complex near Moscow who was looking for a promising long-term high-tech project. He was having a hard time finding a team of scientists who fit the bill. “The entire Soviet system trained scientists to spend,” Gusev notes. “Researchers would take money, spend it on what they wanted, and refuse to answer to anybody.”
Golant’s invention proved an excellent investment. Soon, The Business-Unitech Company was set up for the project.
Major investments and extensive efforts on the part of the team were made to create a product with as high an added value as possible, a complete, finished temperature sensor. “We are a small company and knowingly decided to focus on the most interesting market segment rather than scatter our energy,” Gusev says.
Temperature sensors are the very area where the innovation laboratory has evident market advantages. Apart from its range of measurable temperatures, the sensor possesses a multitude of other indisputable merits. Golant’s temperature sensor has a measurement accuracy twice as high as that of other sensors available on the market (in particular those manufactured by the well-known CiDRA).
Business-Unitech has identified several industries where the new sensor could prove indispensable. First of all, the sensor could be used in the oil and natural gas industry. Since the sensor itself doesn’t require electricity (the laser that triggers the optical beam can be located several kilometers away), it never short circuits and can be placed inside oil storage facilities.
Power plants are another area where the sensors can be applied, as they can be used to control the temperature of a generator’s windings. Electromagnetic interference, a big problem for the industry, doesn’t have any impact on the optical sensor.
The same useful feature makes the sensor indispensable in industrial microwaves used in agriculture to dry grain or wood. The nuclear power and aircraft construction could also benefit from the new product, as the nitrogen-alloyed fiber is resistant to radiation.
However, the sensor has proven difficult to produce en masse. For the time being, the investment stage is still underway. In addition to Gusev’s immediate investments, scientific funds have contributed to the project. In 2002, the Research Center for Fiber Optics and Business-Unitech were awarded grants from Russia’s two most influential scientific funds – RFFI and the Assistance Fund. Annual investments totaled 1.9 million rubles. In 2003, the project to set up production of high-temperature Bragg lattice-based sensors received the Intel Innovation Prize at our competition (the invention clearly didn’t leave specialists from Intel Capital, the world’s largest corporate venture fund, cold).
Sensor production is due to start in the first half of 2004. Gusev is currently equipping a separate laboratory to the tune of more than $100,000. Active experiments are continuing at the same time. The physicists are constantly improving on their invention and increasing the sensor’s accuracy up to a tenth of a degree. They have made their own chip to analyze the sensor’s readings and are writing software for users of the new device. In the first half of the next year, Business-Unitech will be in a position to offer its first commercial product. Potential customers may emerge even earlier, perhaps immediately after the team attends the Optical Fiber Communications conference, the world’s most prestigious OFC forum, in Los Angeles in February 2004. Gusev, however, is impatient: he’s already thinking about expanding the product line to tension and pressure sensors.

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