Water helps create a broad-spectrum supercontinuous white laser that covers an impressive range of wavelengths. Researchers have made significant progress in creating ultra-wideband white laser sources that cover a wide range of wavelengths from ultraviolet to far infrared. These advanced lasers are used in a variety of fields, including broad imaging, femtochemistry, telecommunications, laser spectroscopy, sensing, and ultrafast science.

However, the search faces problems, especially in the selection of suitable nonlinear environments. Conventional solid-state materials, although effective, are prone to optical damage under high power conditions. Although gaseous media are resistant to damage, they often have low efficiency and technical difficulties.

Innovative solutions with water as a non-linear medium

Unusually, researchers at the South China University of Technology have recently turned to water as a nonlinear medium. Abundant and cheap water is resistant to optical damage even under the influence of powerful lasers. As reported in Gold Open Access magazine Advanced Photonics Nexuswater-induced spectral broadening includes enhanced self-phase modulation and stimulated Raman scattering, resulting in a 435 nm 10 dB supercontinuous white laser covering an impressive 478-913 nm range.

Achievements of Water-CPPLN cooperation

Continuing the innovation, the researchers combined water with a periodically polarized lithium niobate (CPPLN) crystal, known for its robust second-order nonlinear power. This partnership not only expanded the frequency range of the supercontinuous white laser, but also flattened its output spectrum. Related senior author Prof. According to Zhi-Yuan Li, “The cascaded water-CPPLN module provides a robust, stable, and low-cost technical route to realize the “three heights” of a white laser with intense pulse energy, high spectral uniformity, and ultra-wide bandwidth.”

The results of this collaboration between Water and CPPLN are promising. With a pulse energy of 0.6 mJ and a 10 dB bandwidth spanning an octave (413-907 nm), this ultra-wideband supercontinuum source has the potential for ultrafast spectroscopy and hyperspectral imaging. Li states: “It offers high resolution of physical, chemical and biological processes in extreme spectral ranges with a high signal-to-noise ratio. It is a long-lasting, highly stable and low-cost white with dense pulse energy, high spectral uniformity and ultra-wide bandwidth.” “It opens up new opportunities in scientific research and applications by opening up an effective way to create lasers.”