The achievement of coherent beam combination is of paramount importance in the advancement of high-power laser systems across various fields, such as defense and communication. In this context, we present a novel filled-aperture coherent beam combiner that integrates essential components including polarization-maintaining fiber elements, Electro-Optic Modulators (EOMs), Erbium-Doped Fiber Amplifiers (EDFA), a Multi-Plane Light Converter, and a feedback loop employing the Stochastic Parallel Gradient Descent (SPGD) algorithm. By leveraging the SPGD algorithm, we attain precise control over the EOMs, enabling stable optical output power. Our experimental results demonstrate the effectiveness of this approach, as it achieves coherent combination of up to six input channels with high efficiency. Additionally, we observe negligible power loss throughout the duration of the process, while maintaining precise control over thermal and mechanical perturbations. One advantage of this MPLC technology is its direct scalability across different wavelengths. This feature enhances its applicability in a wide range of laser systems.
Coherent combination of laser beams is crucial for high-power laser development in various applications, including defense and communication systems. A filled-aperture coherent beam combiner is introduced, which includes polarization-maintaining fiber components, Electro-Optic Modulators, EDFA, a Multi-Plane Light Converter, and a feedback loop based on the Stochastic Parallel Gradient Descent algorithm. The SPGD algorithm allows precise control of the EOMs to achieve stable optical output power. The experimental results demonstrate the proposed approach achieves coherent combination of up to 6 input channels with high efficiency, negligible power loss duration, and precise control over thermal and mechanical perturbations. This technology is directly scalable for different wavelengths.
We describe how to improve micro-processing using Second Harmonic Generation of a Ultra-Short Pulse laser combined with a Multi-Plane Light Conversion beam-shaper.
Manufacturing at 515nm presents advantages compared to 1030nm : extended depth of field, higher sharpness, and higher ablation efficiency for some materials. The beam-shaper provides a square top-hat with a 1/10 sharpness and an extended depth of field up to 10 times higher compared to other beam-shaping technologies.
We describe process results of different metal samples: LIPSS generation with a 100µm square targeting a period down to 0,5µm and holes drilling holes of a diameter smaller than 10µm.
The microfluidics field, due to its various possibilities in the study of chemical and biological reactions with only few consumables, is expanding significantly. A flexible solution has been developed based on Ultra-Short Pulsed laser technology to engrave different microfluidic channels on a chip, and to seal them.
We describe here a solution to improve the welding’s speed and quality based on a tailored beam shaping with Multi-Plane Light Conversion (MPLC) technology. The fully reflective module is used with a high-power femtosecond laser. The optical performance of the module and achieved improvement on the welding are detailed.
Micro processing applications using femtosecond lasers have developed thanks to the quality of the process. A challenge still to be addressed is the capability to deliver the beam through a fibre. One solution is the use of hollow-core inhibited coupling fibres, nevertheless its use requires a beam stabilization to insure a stable operation.
This study attempts to qualify two beam stabilisation systems: two piezo motors coupled with four quadrant detectors and Cailabs’ all-optical mode-cleaner system based Multi-Plane Light Conversion (MPLC) technology. To do such output fibre transmission efficiency and beam quality are investigated under controlled fluctuation of beam pointing.
Multi-Plane Light Conversion (MPLC) is an innovative shaping technique which allows theoretically lossless complex beam shapes. The free-space reflective design is particularly well suited to Ultra-Short Pulse (USP) laser-based processes challenges. We demonstrate the system high stability over long processing times thanks to a mode cleaning feature.
Here we show micro-cutting and engraving tests carried out on stainless-steel and brass with a high power, industrial, USP laser having squared, and circular top-hat profile generated using MPLC technology. Thanks to the sharp edges of the profile, a sensible reduction of the taper and optimization of the overlapping is observed
Generation of nano or micro-scale structures on materials surface enables new functions and properties, such as super-hydrophobicity by lotus effect, surface blackening by light trapping, modification of surface tribological properties, etc. which are in high demand for a wide variety of industrial fields. Amongst the surface functionalization techniques, Ultra-Short Pulse lasers have been proven to be a reliable tool to create Laser Induced Periodic Surface Structures (LIPSS). Exploitation of LIPSS for industrial purposes poses some key problems like up scaling over large area with high repeatability and high throughput. Beam shaping could be a key element to overcome these issues. Specific shapes, such as top-hat line shape, could enable at once uniform processing over large surface with the consequence to reduce the processing time. Multi-Plane Light Conversion (MPLC) is an innovative technique of beam shaping which allows theoretically lossless complex beam shapes with a high control over amplitude and phase. The free-space reflective design allows for high beam shaping quality whilst maintaining the ultra-short property of the laser pulses, which is not usually achievable through other beam shaping methods. Here we show the results obtained over Stainless-Steel using an industrial femtosecond laser with a tophat line of 30μm × 594 μm intensity profile generated using MPLC technology. The beam has been delivered over the Stainless-Steel surface with a galvo scanner and focused through an f -theta lens of 100 mm. Surface morphology has been investigated via SEM and the processing time has been compared to conventional round Gaussian Beams
The nature of a quantum network, in particular in the continuous variable regime, is governed not only by the light quantum state but also by the measurement process. It can then be chosen after the light source has been generated. Multimode entanglement is not anymore an intrinsic property of the source but a complex interplay between source, measurement and eventually post processing. This new avenue paves the way for adaptive and scalable quantum information processing. However, to reach this ambitious goal, multimode degaussification has to be implemented.
Single-photon subtraction and addition have proved to be such key operations, but are usually performed with linear optics elements on single-mode resources. We present a device able to perform mode dependant non Gaussian operation on a spectrally multimode squeezed vacuum states. Sum frequency generation between the state and a bright control beam whose spectrum has been engineered through ultrafast pulse-shaping is performed. The detection of a single converted photon heralds the success of the operation.
The resulting multimode quantum state is analysed with standard homodyne detection whose local oscillator spectrum is independently engineered. The device can be characterized through quantum process tomography using weak multimode coherent states as inputs. Its single-mode character can be quantified and its inherent subtraction modes can be measured.
The ability to simultaneously control the state engineering and its detection ensures both flexibility and scalability in the production of highly entangled non-Gaussian quantum states.
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