scholarly journals Kilometre-scale, kilowatt average power, single-mode laser delivery through hollow core fibre: overcoming nonlinear limits of glass fibre

2021 ◽  
Author(s):  
Hans Christian Mulvad ◽  
Seyed mohammad Abokhamis Mousavi ◽  
Viktor Zuba ◽  
Lin Xu ◽  
Hesham Sakr ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Beam Quality ◽  
Average Power ◽  
Single Mode ◽  
Power Delivery ◽  
Hollow Core ◽  
Single Mode Laser ◽  
Core Fibre ◽  
Order Of Magnitude ◽  
Beam Delivery

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

scholarly journals Passively Q-Switched and Mode-Locked Er3+-Doped Ring Fiber Laser with Pulse Width of Hundreds of Picoseconds

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 560
Author(s):  
Ji Wang ◽  
Wenwu Zhang ◽  
Tianrun Zhang
Keyword(s):  
Fiber Laser ◽  
Continuous Wave ◽  
Average Power ◽  
Basic Research ◽  
Single Mode ◽  
Frequency Stability ◽  
Wave Mode ◽  
Switching Frequency ◽  
Maximum Output ◽  
Power Instability

Greatly improving the energy of a single mode-locked pulse while ensuring the acquisition of the width of short pulses will contribute to the application of mode-locked pulse in basic research, such as precision machining. This report has investigated a Q-switched and mode-locked (QML) erbium doped ring fiber laser based on the nonlinear polarization rotation (NPR) technology and a mechanical Q-switched device. Without the working of the mechanical Q-switched device, the fiber laser exported the continuous-wave mode-locked (CWML) pulse, with a width of 212.5 ps, and a repetition frequency of 81.97 MHz. For the CWML operation, the maximum output average power is 25.7 mW, and the energy is only 0.31 nJ. For the QML operation, 18.03 mW average power is achieved at the Q-switching frequency of 100 Hz. The energy of the QML pulse is increased by over 1100 times to 360.6 nJ. The width of the QML pulse is 203.1 ps measured by an autocorrelation curve, with the time-band product (TBP) being 0.598. The power instability is 0.5% (RMS) and 0.7% (RMS), respectively, for CWML and QML operation within 120 min. Furthermore, the spectral signal-to-noise ratio is about 60 dB. For the QML operation, the power instability is 0.48% (RMS) within 60 s and 0.37% (RMS) within 10 s. After frequency stabilization, the frequency fluctuation is ±100 Hz in the long-term of 1200 s, with the frequency stability (FS) calculated to be 2.44 × 10−6. It indicates that the QML fiber laser has good power stability and frequency stability.

scholarly journals Low-loss single-mode hybrid-lattice hollow-core photonic-crystal fibre

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Foued Amrani ◽  
Jonas H. Osório ◽  
Frédéric Delahaye ◽  
Fabio Giovanardi ◽  
Luca Vincetti ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Single Mode ◽  
Confinement Loss ◽  
Hollow Core ◽  
Low Loss ◽  
Fibre Optics ◽  
Photonic Crystal Fibre ◽  
Single Mode Operation ◽  
Mode Operation ◽  
Beam Delivery

AbstractRemarkable recent demonstrations of ultra-low-loss inhibited-coupling (IC) hollow-core photonic-crystal fibres (HCPCFs) established them as serious candidates for next-generation long-haul fibre optics systems. A hindrance to this prospect and also to short-haul applications such as micromachining, where stable and high-quality beam delivery is needed, is the difficulty in designing and fabricating an IC-guiding fibre that combines ultra-low loss, truly robust single-modeness, and polarisation-maintaining operation. The design solutions proposed to date require a trade-off between low loss and truly single-modeness. Here, we propose a novel IC-HCPCF for achieving low-loss and effective single-mode operation. The fibre is endowed with a hybrid cladding composed of a Kagome-tubular lattice (HKT). This new concept of a microstructured cladding allows us to significantly reduce the confinement loss and, at the same time, preserve truly robust single-mode operation. Experimental results show an HKT-IC-HCPCF with a minimum loss of 1.6 dB/km at 1050 nm and a higher-order mode extinction ratio as high as 47.0 dB for a 10 m long fibre. The robustness of the fibre single-modeness is tested by moving the fibre and varying the coupling conditions. The design proposed herein opens a new route for the development of HCPCFs that combine robust ultra-low-loss transmission and single-mode beam delivery and provides new insight into IC guidance.

scholarly journals High-efficiency multipass Ti:sapphire amplifiers for a continuous-wave single-mode laser

1991 ◽  
Vol 16 (3) ◽  
pp. 144 ◽  
Author(s):  
Patrick Georges ◽  
Frederick Estable ◽  
François Salin ◽  
Jean Philippe Poizat ◽  
Philippe Grangier ◽  
...  
Keyword(s):  
High Efficiency ◽  
Continuous Wave ◽  
Single Mode ◽  
Mode Laser ◽  
Single Mode Laser

3.53 kW average power all-fiber amplifier with 0.16nm narrow-linewidth single-mode beam quality

2018 ◽  
Author(s):  
Yi Shi ◽  
Quihui Chu ◽  
Li'e Ouyang ◽  
Feng Jing ◽  
Jianjun Wang ◽  
...  
Keyword(s):  
Beam Quality ◽  
Average Power ◽  
Single Mode ◽  
Fiber Amplifier ◽  
Narrow Linewidth ◽  
Mode Beam

Demonstration of 1.51µm InAs/InP(311)B quantum dot single-mode laser operating under continuous wave

2007 ◽  
Vol 1 (6) ◽  
pp. 255-258 ◽  
Author(s):  
G. Moreau ◽  
F. Pommerau ◽  
S. Bouchoule ◽  
K. Tavernier ◽  
A. Ramdane ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Continuous Wave ◽  
Single Mode ◽  
Mode Laser ◽  
Single Mode Laser

Source-Corrected Two-Photon Excited Fluorescence Measurements between 700 and 880 nm

1998 ◽  
Vol 52 (4) ◽  
pp. 536-545 ◽  
Author(s):  
W. G. Fisher ◽  
E. A. Wachter ◽  
Fred E. Lytle ◽  
Michael Armas ◽  
Colin Seaton
Keyword(s):  
Continuous Wave ◽  
Group Velocity Dispersion ◽  
Dispersion Compensation ◽  
Average Power ◽  
Single Mode ◽  
Wavelength Dependence ◽  
Power Correction ◽  
Two Photon ◽  
Fluorescence Measurements ◽  
Photon Excitation

Passively mode-locked titanium:sapphire (Ti:S) lasers are capable of generating a high-frequency train of transform-limited subpico-second pulses, producing peak powers near 105 W at moderate average powers. The low energy per pulse (<20 nJ) permits low fluence levels to be maintained in tightly focused beams, reducing the possibility of saturating fluorescence transitions. These properties, combined with a wavelength tunability from approximately 700 nm to 1 μm, provide excellent opportunities for studying simultaneous two-photon excitation (TPE). However, pulse formation is very sensitive to a variety of intracavity parameters, including group velocity dispersion compensation, which leads to wavelength-dependent pulse profiles as the wavelength is scanned. This wavelength dependence can seriously distort band shapes and apparent peak heights during collection of two-photon spectral data. Since two-photon excited fluorescence is proportional to the product of the peak and average powers, it is not possible to obtain source-independent spectra by using average power correction schemes alone. Continuous-wave, single-mode lasers can be used to generate source-independent two-photon data, but these sources are four to five orders of magnitude less efficient than the mode-locked Ti:S laser and are not practical for general two-photon measurements. Hence, a continuous-wave, single-mode Ti:S laser has been used to collect a source-independent excitation spectrum for the laser dye Coumarin 480. This spectrum may be used to correct data collected with multimode sources; this possibility is demonstrated by using a simple ratiometric method to collect accurate TPE spectra with the mode-locked Ti:S laser. An approximate value of the two-photon cross section for Coumarin 480 is also given.

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