Researchers at South Africa's Council for Scientific and Industrial Research (CSIR) have developed the world's first digital laser. This innovation is regarded as a milestone in laser technology and could spur future laser-related innovations.
Laser devices normally consist of mirrors, energy (light) and a casing containing a medium, for example crystal or glass. The medium changes the frequency of the light to create a laser beam with the perfect characteristics for these different applications.
In conventional lasers, the shape of the light that comes out is either not controlled at all, or a single shape is selected by expensive optics. For example, when a medical doctor undertakes surgery, the beam must be appropriate for precision-cutting.
Alternatively, the laser light can be shaped after exiting the laser using a spatial light modulator – a liquid crystal display (LCD) that can be digitally addressed with grey-scale images representing the desired change to the light. The CSIR team has demonstrated for the first time that this can all be done inside the laser.
Digital laser uses the LCD as one of its mirrors that is fitted at one end of the laser cavity. Just as with LCD televisions, the LCD inside the laser can be sent pictures to display. When the pictures change on the LCD inside, the properties of the laser beams that exit the device change accordingly.
By sending an appropriate picture to the LCD, any desired laser beam could be created inside the laser device. This is a significant advancement from the traditional approach to laser beam control, which requires costly optics and realignment of the laser device for every beam change.
Since this is all done with pictures, the digital laser represents a paradigm shift for laser resonators.
The dynamic control of laser modes could open up many future applications, from communications to medicine. Our device represents a new way of thinking about laser technology and we see it as a new platform on which future technologies may be built.
According to csir.co.za