Coherent Random Fiber Laser-Enabled Super-Resolution Spectroscopy

Inspired by single-molecule localization microscopy, super-resolution spectroscopy has been achieved by sparse sampling in the spectral domain, where a light source capable of randomly emitting sparse peaks plays a crucial role. Due to the intrinsic feedback mechanism of disordered light scattering, random lasers can provide the desired emission characteristics that facilitate reconstructing the detailed spectral profiles of samples. Here, we propose an all-fiber-configured coherent random laser for spectral measurement to break the instrumental response limitation of spectral detection systems. The laser remains in a chaotic regime and exhibits self-modulating spectral behavior by introducing an elaborately designed spectral tailoring element inside the cavity. The statistical number and distribution of the random peaks over the emission spectrum can be manipulated by adjusting the pump power. In addition, the laser exhibits several attractive features, such as low pumping threshold, narrow-line-width lasing modes, flexible operating wavelength range, high optical signal-to-noise ratio, and easy compatibility with optical fiber systems. Using a low-resolution spectrograph, we experimentally demonstrate super-resolution spectrum reconstruction, obtaining a spectral enhancement of around 3.3. This work provides a powerful illumination source and realization method for high-resolution spectroscopy, which is an essential tool for future optical information applications.