Background
The term “micro electro mechanical systems (MEMS)” may be unfamiliar but these products already play an indispensable role in daily life. Compact, lightweight MEMS sensors are used as acceleration sensors for smartphones and game consoles and as position sensors for automobiles and robots. Yokogawa has been developing and manufacturing MEMS pressure sensors since the 1980s. By using technology cultivated in the field, Yokogawa has developed a MEMS wavelength tunable laser light source.
This light source is a key device that can be used for optical measurements in the fields of gas, the environment, and medical care. By developing measurement systems that use this device, Yokogawa is helping to build a sustainable society.
Technology
MEMS-VCSEL
By combining vertical cavity surface emitting laser (VCSEL) and silicon MEMS (Si-MEMS) technologies, Yokogawa has developed a compact, high-speed laser light source whose wavelength is tunable over a wide range.
The operating principle is as follows: when a voltage is applied to the upper and lower layers of the Si-MEMS substrate, static electricity occurs and attracts a thin film of silicon on the upper layer toward the lower layer. As a result, the optical resonator becomes longer and the laser oscillation wavelength increases accordingly. With this mechanism, wavelengths can be swept continuously, which is particularly useful for optical measurements.
Gas laser spectroscopic system for plants
By incorporating a MEMS-VCSEL unit, Yokogawa developed a laser spectroscopic system for plant control. Thanks to its tunable wavelength over a wide range and high-speed operation, the system can measure multiple components of gases at high speed, control a plant in real time, and improve efficiency.
Vision for the future
Optical measurement for a sustainable society
There are increasing concerns about the worsening environment, aging social infrastructure, and growing medical costs. To solve these problems and achieve a sustainable society, various sensors and measuring devices are being developed. Yokogawa’s MEMS wavelength tunable laser light source, which features a tunable wavelength over a wide range, quick response, and small footprint, is playing an invaluable role in these sensors and measuring devices.
- High-sensitivity gas laser spectroscopy for real-time measurement of gases discharged from plants
- Distortion and security sensors for social infrastructure such as buildings and bridges
- High-speed, high-sensitivity optical coherence tomography (OCT) laser (medical use)
- Optical communications and measuring devices
- Environmental monitoring
