Mode-resolved gain analysis and lasing in multi-supermode multi-core fiber laser

Abstract

Multi-core fibers (MCFs) with coupled-cores are attractive large-mode area (LMA) specialty fiber designs that support the propagation of a few transverse modes often called supermodes (SMs). Compared to other LMA fibers, the uniqueness of MCF arises from the higher degrees of design space offered by a multitude of core-array geometries, resulting in extended flexibility to tailor SM properties. To date, the use of MCF as gain media has focused on lasers that operate in only one selected SM, typically the lowest order in-phase SM, which considerably limited the potential of these multi-core structures. Here, we expand the potential of MCF lasers by investigating multi-SM amplification and lasing schemes. Amplifier and laser systems using a 7 coupled-cores Yb-doped MCF as gain medium were successfully designed and assembled. Individual SM could be decomposed using the correlation filter technique mode analysis and the modal amplification factors (γi) were recorded. With access to amplification characteristics of individual transverse modes, a monolithic MCF laser was demonstrated that operates simultaneously on the two SMs carrying the highest optical gain.

Multicore Fiber Sensors for Simultaneous Measurement of Force and Temperature

“…Here, both MMI minima are still clearly visible, however this chain could be further optimized by slightly tuning the length of the MCF sections to further separate the MMI minima from each other. The dependence of the transmission minima on the MCF length was calculated by Jollivet et al [13]. Both MCF devices can then be individually monitored using a single transmission measurement.…”

Learning to decompose the modes in few-mode fibers with deep convolutional neural network

“…wave front [7] and beam propagation factor [8]. Recent years, MD techniques have been widely used in many applications, such as optimizing fiber-to-fiber coupling [9], analyzing mode-resolved gain [10,11] or bend loss [12], diagnosing temporal mode instabilities [13,14], measuring mode transfer matrix [15,16] and realizing adaptive mode control [17,18].In the past few years, various MD methods have been proposed with different techniques, such as spatially and spectrally resolved imaging [19], frequency domain cross-correlated imaging [20], ring-resonators [21], low coherence interferometry [22], correlation filter [23] and digital holography [24]. Although these methods can achieve accurate results, they require consuming post-data processing or intense experimental measurements.…”

Multi-Core Optical Fibers: Theory, Applications and Opportunities

“…All-fiber designs of optical lasers, amplifiers and sensors using MCFs have been extensively investigated in recent years [32,[101][102][103][104][105][106][107][108][109][110][111]. In particular, the multi-mode interference (MMI) which can be observed through a chain SMF-MCF-SMF is widely employed in lasers, amplifiers and optical sensors to improve the performance of classical designs based on SCFs [32,104].…”