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Mitsubishi Electric Testing Wind LIDAR and Water Vapor DIAL,
Including Laser Amplifier with World's Highest Output, for Early
Forecasting of Torrential Rain
Will facilitate better forecasting of torrential rain
TOKYO, October 11, 2018 – Mitsubishi Electric Corporation (TOKYO: 6503) announced today that it has
started demonstration testing of a new system equipped with wind LIDAR (light detection and ranging) andwater vapor DIAL (differential absorption LIDAR) measuring methods for the early forecasting of torrentialrain. The system incorporates a newly developed high-output-power waveguide laser amplifier that delivers
what is believed to be the world’s highest output, 15.8 millijoules, using an a single-frequency pulse laser inthe 1.5μm wavelength, which is not harmful to human eyes. The tests are expected to demonstrate that thesystem simultaneously measures water vapor in the air and upward air currents, which cause cumulonimbus
clouds, quicker, more accurately and in a wider range compared to conventional alternatives. Going forward,
Mitsubishi Electric expects to make further improvements prior to launching a commercial system for theextra-early forecasting of torrential rain.
The wind LIDAR and water vapor DIAL demonstration system will be exhibited at CEATEC JAPAN 2018 atMakuhari Messe exhibition complex in Chiba Japan from October 16 to 19.

Demonstration water vapor DIAL and wind LIDAR

Principles of water vapor DIAL and wind LIDAR measurements

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The new system, which is based on a conventional wind LIDAR that Mitsubishi Electric released on May 28,
2014, has been enhanced for the measurement of water atmospheric vapor. It transmits laser beams from theground to simultaneously measure the amount and distance of water vapor as well as the speed and directionof wind.

Water vapor measurement

Features of New DIAL and LIDAR System1)

Downsized laser amplifier with planar waveguide configuration- Long optical path for amplification is folded to downsize and the laser beam is confined in the planar

waveguide. The design is both compact (30 mm x 23 mm x 8 mm) and achieves an amplification factorof 400 times, which has similar characteristics of optical fiber amplifiers and 27% greater than that ofconventional amplifiers which use solid-state laser materials.
- The high-power lasers are achieved with compact waveguides that use a double-clad waveguidestructure composed of multiple layers.
2)

Increased output for detecting tiny amounts of laser absorption in water vapor- Use of a single-frequency pulse laser in the 1.5μm wavelength facilitates highly sensitive detection.
- Mitsubishi Electric’s original design suppresses both scattering losses due to the high output of a single
wavelength and energy dissipation due to high amplification.
- Output is a world's leading 15.8 mJ (millijoules), which is about three times greater than that of thecompany’s existing wind LIDAR.

2/33)No danger to human eyes
- Safe outdoor measurements are assured by using the 1.5μm wavelength, which is not harmful to humaneyes.

Structure of planar waveguide laser amplifier

Extreme weather-related disasters are on the rise worldwide. In the case of torrential rain, early warnings mustbe issued as early as possible to enable communities to evacuate to safety. With conventional weather radars,
however, cumulonimbus clouds can only be observed after they have formed, making it difficult to forecast
torrential rain in time to carry out evacuations adequately. To facilitate better forecasting, Mitsubishi Electrichas been extensively testing and refining the measurement accuracy of new water vapor DIAL and wind
LIDAR methods, which are now in the stage of demonstration testing.

Patents
The patents for the developed technology announced in this press release number seven in Japan and seven inother countries.

###About Mitsubishi Electric Corporation
With nearly 100 years of experience in providing reliable, high-quality products, Mitsubishi Electric
Corporation (TOKYO: 6503) is a recognized world leader in the manufacture, marketing and sales of electricaland electronic equipment used in information processing and communications, space development and satellitecommunications, consumer electronics, industrial technology, energy, transportation and building equipment.
Embracing the spirit of its corporate statement, Changes for the Better, and its environmental statement, EcoChanges, Mitsubishi Electric endeavors to be a global, leading green company, enriching society withtechnology. The company recorded consolidated group sales of 4,444.4 billion yen (in accordance with IFRS;
US$ 41.9 billion*) in the fiscal year ended March 31, 2018. For more information visit:
www.MitsubishiElectric.com*At an exchange rate of 106 yen to the US dollar, the rate given by the Tokyo Foreign Exchange Market on
March 31, 20183/3