Recently, researchers from Massachusetts have developed a novel fiber laser system that has a compact size and is able to emit light with a high level of spectral purity. The fiber laser’s light remains unchanged in environmental conditions. The researchers confirm that the novel laser system will be useful for future scientific applications that include:
- clock improvement for Global Positioning Systems or GPS;
- determination of space gravitational waves;
- quantum computing.
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Advantages of the fiber laser system
The fiber laser system has a lot of advantages, such as small size, the ability to emit exceptionally pure light, and unresponsiveness to the environment. Also, laser technology allows creating an environmentally stable, narrow, portable linewidth laser due to the fiber used for the laser module. A laser system is developed to emit purely in one wavelength, but there are still environmental influences that cause noise, changing the light frequency. The researchers using a novel technique have developed an optical fiber laser with a spectral linewidth narrower than ever achieved by a fiber or semiconductor laser.
Principle of operation
The main goal of the development is the replacement of ultra-low expansion (ULE) cavity lasers with a compact one that isn’t sensitive to environmental noise. The principle of laser module operation includes the use of a short loop of optical fiber configured as a ring resonator.
Performance and applications
Since fiber laser systems are portable and solid, and also have immunity to environmental changes, the researchers made the combination of fiber laser advantages with the nonlinear optical effect to develop a laser with a linewidth of just 20 hertz, compared to other laser systems, whose linewidths range from 1000 to 10,000 hertz, and semiconductor lasers’ linewidth is around 1 million hertz.
The development of laser systems can be used for the creation of a new generation of optical atomic clocks used for GPS-enabled devices. These clocks will provide a more accurate pinpoint of the arrival time of the signal and improve the location accuracy of today’s GPS systems.
This device will be quite useful for interferometers like the ones used by the Laser Interferometer Gravitational-wave Observatory or LIGO, to detect gravitational waves coming from colliding black holes or collapsing stars.