Researchers at the University of Bath have developed a new type of laser pointer that can emit mid-infrared spectra with a spectral range of 3.1 microns to 3.2 microns. The research results will bring new applications for mid-infrared lasers. Mid-infrared lasers are currently mainly used in spectroscopy, environmental remote sensing, and explosive detection.
This new laser is mainly composed of gas and fiber lasers. Researchers put a suitable gas into the hollow core fiber to develop this fiber gas laser that emits mid-infrared spectrum. The key factor for the success of this research and development is the use of hollow-core silicon fibers that have excellent effects in the mid-infrared spectrum during the research and development process. Hollow core optical fiber is a new type of optical fiber, which can use internal glass structure to confine light to the hollow core of optical fiber.
Because most of the light running in the hollow core fiber is in the hollow core position, these fibers can prevent silica glass from absorbing light with wavelengths exceeding 2.8 microns. Because of its low price, easy production, and excellent strength, silica is the material of choice for optical fibers.
The researchers said that a new type of fiber laser can be constructed by using their new hollow core fiber. The laser needs to excite the target material through an electric current or another laser. The researchers used acetylene gas; because acetylene gas can emit mid-infrared spectrum and can be excited or pumped, it can be used in the communications industry. Hollow-core optical fibers provide the possibility to capture light and gas in the same place, so in this case, light and gas can interact over a long distance (10 meters to 11 meters).
Researchers at the University of Bath and other research institutions have demonstrated earlier that the gas in the optical fiber can interact with light to produce mid-infrared spectrum emission. In this study, the researchers added a feedback fiber. It is precisely because of the use of this feedback fiber that the device becomes a real green laser pointer.
The feedback fiber brings back a small amount of light formed in the fiber containing acetylene gas, and then forms another round of optical amplification through these lights, thereby forming the pump power required by the laser beam. One advantage of the new design is the use of mature communication diode lasers that are practical, inexpensive and provide high power. Researchers plan to use high-power pump lasers to increase the power of fiber gas lasers.