High‐Power Multimode Random Fiber Laser for Speckle‐Free Imaging

Abstract

New light sources with low spatial coherence and high brightness are crucial for high‐quality imaging. In this paper, such a light source is reported, which is formed by combining random lasing used as seed light with a multimode fiber (MMF) mediated master oscillator power amplifier (MOPA) for power scaling and spatial decoherence. Experimental results show that the proposed multimode random fiber laser (MM‐RFL), with low noise, high spectral density, and high power efficiency, can achieve a maximum output power of 100.6 W and speckle contrast of as low as 0.037. Furthermore, MM‐RFL‐based speckle‐free imaging is demonstrated. The imaging quality can be improved by increasing the output power of the MM‐RFL as its spatial coherence decreases with an increasing number of effective modes excited in the MMF. Such a MM‐RFL provides a powerful light source for speckle‐free imaging applications where high power and low spatial coherence are essential for high‐quality imaging.

Boundary Feedback Fiber Random Microcavity Laser Based on Disordered Cladding Structures

“…Therefore, random lasers with high light harvesting and scattering capabilities have excellent upfront potential in achieving ultralow threshold and high-quality factor lasing. Additionally, the laser directivity, mode characteristics, and other parameters exhibit unpredictable disordered output characteristics, providing a greater degree of freedom for the parameter control of random lasers [31][32][33].…”

Brillouin Interaction between Two Optical Modes Selectively Excited in Weakly Guiding Multimode Optical Fibers

“…This powerful technique is contactless and label-free, making it especially suitable for biomedical applications [ 8 ]. Randomized light fields [ 9 , 10 ] also open up new forms of optical imaging based on Brillouin scattering. A standard multimode optical fiber provides randomized light propagation, whereas random lasing is available through the Rayleigh–Brillouin cooperative process [ 11 ].…”

Random fiber laser based on femtosecond weak grating array

“…After more than ten years of development, the theoretical basis of RFL has become mature, and the research focus has gradually expanded to the application field. In recent years, a series of achievements have been made in the fields of optical fiber sensing [2][3][4][5], optical fiber communication [6], speckle free imaging [7,8] and so on.…”