High-power laser delivery with near-diffraction-limited beam quality is typically limited to tens of metres distances by nonlinearity-induced spectral broadening inside the glass core of delivery fibres. Anti-resonant hollow-core fibres offer not only orders-of-magnitude lower nonlinearity but also loss and modal purity comparable to conventional beam-delivery fibres. Using a single-mode hollow-core nested anti-resonant nodeless fibre with 0.74 dB km−1 loss, we demonstrate the delivery of 1 kW of near-diffraction-limited continuous-wave laser light over a 1 km distance, with a total throughput efficiency of ~80%. From simulations, a further improvement in transmitted power or length of more than one order of magnitude should be possible in such air-filled fibres, and considerably more if the core is evacuated. This paves the way to multi-kilometre, kilowatt-scale power delivery that is potentially useful not only for future manufacturing and subsurface drilling but also for new scientific possibilities in sensing, particle acceleration and gravitational wave detection. Microstructured optical fibre is shown to be able transmit high-power laser light over long distances with high throughput efficiency.

We present the first demonstration of optical coupling between hollow core fibers and Silicon Photonics circuits. We achieved moderate excess coupling loss with respect to SMF-28 and achieved 25 Gb/s data transmission over NANF fibers. © 2021 The Authors

This dataset supports the paper: Taranta, A., Numkam Fokoua, E., Abokhamis Mousavi, S. et al. Exceptional polarization purity in antiresonant hollow-core optical fibres. Nat. Photonics (2020). https://doi.org/10.1038/s41566-020-0633-x

The sensitivity of an interferometric fiber optic gyroscope (IFOG) scales with the length of the sensing optical path. Thus, IFOG development history has seen much work devoted to shrinking ever-increasing lengths of optical fiber into a fixed volume. Indeed, the success of the IFOG as a guidance and navigation technology is founded, to a large extent, on the many advancements in fiber-optics which were required to compact numerous state-of-the-art components - including a multi-kilometer length of optical fiber - to within the size of a teacup. An exciting technology which promises to continue this trend is multicore optical fiber, in which multiple, independent optical waveguides (cores) are placed within the same glass cladding which would ordinarily contain only one core. The dense arrangement of cores in such fibers can be exploited in an IFOG by connecting them in series, and thereby increasing the instrument sensitivity proportionally. As originally proposed by Bergh [1], these features present an opportunity to increase sensitivity while reducing the sensor footprint and simplifying the optical fiber coil - a key driver of cost and complexity in IFOGs. Here we detail performance characteristics of an all-fiber multicore IFOG employing a bend-insensitive, single-mode, 7-core fiber in the sensing coil. Like the recent, first-ever demonstration by Mitani et al. [2], [3], we employ an open-loop testbed architecture with a depolarized sensing loop, in which fiber cores are connected in series via a pair of multicore fan-in/fan-out devices. Here however, the fan-in/fan-out components are tapered fiber devices, packaged in conventional fiber-optic component sleeves, and with the core interconnections made via standard fusion splices [4]. Measurements of noise and long-term stability of the instrument show that its performance is commensurate with the 7X enhanced sensitivity afforded by the optical path length increase. For this 7-core, 154 m long, 10 cm diameter fiber coil, we show long-term gyro bias stability under 0.02 deg/hr and angle random walk of 2.4 mdeg/√(hr). This compares favorably with both noise models and performance measurements in IFOGs of similar scale factor, thus confirming the sensitivity improvement conferred by use of 7-core fiber. The all-fiber configuration of the sensing loop makes this instrument highly practicable as a drop-in replacement for current IFOGs, with no change to existing front-end designs. Moreover, as multicore fiber technology continues to push the frontiers of optical fiber transmission capacity, future designs may benefit from even greater core multiplicity - an exciting prospect for the next generation of compact, low-cost, high-accuracy IFOGs.

We report fabrication of a Nested Antiresonant Nodeless hollow-core Fibre (NANF) with a minimum loss of 1.3dB/km at 1450nm and a 65nm bandwidth below 1.5dB/km. The 0.5-km long fibre is effectively single moded and is shown capable of data transmission.

Summary form only given. Bismuth (Bi)-doped fiber (BDF) lasers and amplifiers have been demonstrated in different glass hosts (i.e., aluminosilicate, phosphosilicate and germanosilicate) covering the 1150-1800nm wavelength region [1-3]. Pulsed Bi-doped fiber lasers (BDFLs) are of great interest owing to their potential applications in medicine, material processing and optical fiber communications. The first Bi-doped pulsed fiber laser was demonstrated in 2007 with 50ps pulses at 1161nm in a Bi-doped silicate fiber using SESAM as a saturable absorber (SA) [4]. A number of studies have since reported on BDFLs [3-6], however, the pulse dynamics in BDFs have not been fully understood due to the unsaturable loss and excited state absorption present in these fibers [7]. In this paper, we present an all fiber self-mode-locked BDFL operating at 1340nm with a minimum pulse width of 1.5ns, the first demonstration of its kind. ΦΓΦ

We demonstrate a 1340 nm mode-locked Bismuth (Bi)-doped fiber laser without any saturable absorber. The effect of pump power on pulse width is studied, and a variation from 1.5 to 3 ns is reported. The output of the mode-locked Bi-doped fiber laser is further amplified using a master oscillator power amplifier configuration, and a peak power of 1.15 W is achieved. Soliton bunching is observed, and a true pulse width of 1.2 ps is reported from the measured autocorrelation trace. Stable operation of the mode-locked laser is verified from the radio-frequency spectrum with a fundamental repetition rate of 6.3 MHz, and SNR of 65 dB.