Optical Vortex Brillouin Laser

Abstract

Optical vortices, which have been extensively studied over the last decades, offer an additional degree of freedom useful in many applications, such as optical tweezers and quantum control. Stimulated Brillouin scattering (SBS), providing a narrow linewidth and a strong nonlinear response, has been used to realize quasi‐continuous wave lasers. Here, stable oscillation of optical vortices and acoustic modes in a Brillouin laser based on chiral photonic crystal fiber (PCF) is reported, which robustly supports helical Bloch modes (HBMs) that carry circularly polarized optical vortex and display circular birefringence. A narrow‐linewidth Brillouin fiber laser that stably emits 1st‐ and 2nd‐order vortex‐carrying HBMs is implemented. Angular momentum conservation selection rules dictate that pump and backward Brillouin signals have opposite topological charge and spin. Additionally, it is shown that when the chiral PCF is placed within a laser ring cavity, the linewidth‐narrowing associated with lasing permits the peak of the Brillouin gain that corresponds to acoustic mode to be measured with resolution of 10 kHz and accuracy of 520 kHz. The results pave the way to a new generation of vortex‐carrying SBS systems with applications in optical tweezers, quantum information processing, and vortex‐carrying nonreciprocal systems.

Functionalized Chiral Twisted Optical Fibers: A Review

“…In addition, twisted fibers have recently made good progress in fields such as amplification and lasers [9,14]. Therefore, when characterizing these devices, researchers will design corresponding experimental plans according to their needs.…”

“…Compared to traditional SMFs, twisted structures in the form of MOFs offer more choices and greater possibilities in the field of twisted fiber applications due to their versatile and flexible structure. In addition to enhanced mode selection, mode field control, and OAM mode generation [48][49][50], chiral twisted microstructured fiber (CTMOF) has also been found to have great potential in fields such as lasers [9], sensing [51][52][53], and transmission [54][55][56]. Here, we have summarized some applications, including chiral twisted photonic crystal fiber (CTPCF), chiral twisted hollow-core fiber (CTHCF), and chiral twisted multicore fiber (CTMCF), and found that microstructured fibers play a crucial role in improving the functionality of twisting.…”

“…This special waveguide structure has generated unique optical phenomena in the transmission of polarized light, generation and transmission of angular momentum beams, and inter-mode interference [6][7][8]. Scientists have used theories such as spiral Bloch theory [9], mode coupling theory [10], and the photoelasticity effect [11] to explain it. Compared with traditional fiber modification methods, twisted fibers provide new features and applications in information capacity expansion [12,13], fiber lasers [9], amplifiers [14], and sensors [7,15,16].…”

“…Scientists have used theories such as spiral Bloch theory [9], mode coupling theory [10], and the photoelasticity effect [11] to explain it. Compared with traditional fiber modification methods, twisted fibers provide new features and applications in information capacity expansion [12,13], fiber lasers [9], amplifiers [14], and sensors [7,15,16].…”