Projects / Programmes
Hybrid high power ps laser
| Code |
Science |
Field |
Subfield |
| 2.21.00 |
Engineering sciences and technologies |
Technology driven physics |
|
| Code |
Science |
Field |
| T165 |
Technological sciences |
Laser technology |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
lasers, pulsed lasers, fiber lasers, optical fibers
Researchers (15)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
32091 |
PhD Vid Agrež |
Technology driven physics |
Researcher |
2014 - 2017 |
86 |
| 2. |
26338 |
PhD Stanislav Čampelj |
Materials science and technology |
Researcher |
2014 - 2017 |
62 |
| 3. |
38760 |
PhD Luka Černe |
Manufacturing technologies and systems |
Technical associate |
2016 - 2017 |
19 |
| 4. |
32339 |
PhD Blaž Kavčič |
Physics |
Researcher |
2014 - 2017 |
33 |
| 5. |
12054 |
PhD Drago Kovačič |
Manufacturing technologies and systems |
Researcher |
2014 - 2017 |
129 |
| 6. |
28041 |
Jolanda Lenardič |
Telecommunications |
Researcher |
2014 - 2015 |
0 |
| 7. |
36738 |
PhD Peter Lukan |
Philosophy |
Researcher |
2014 - 2017 |
17 |
| 8. |
11742 |
PhD Marko Marinček |
Physics |
Researcher |
2014 - 2017 |
59 |
| 9. |
01649 |
PhD Janez Možina |
Manufacturing technologies and systems |
Researcher |
2014 - 2016 |
641 |
| 10. |
37953 |
PhD Jaka Mur |
Manufacturing technologies and systems |
Researcher |
2015 - 2017 |
52 |
| 11. |
35427 |
PhD Jaka Petelin |
Physics |
Researcher |
2016 |
54 |
| 12. |
15646 |
PhD Rok Petkovšek |
Manufacturing technologies and systems |
Head |
2014 - 2017 |
273 |
| 13. |
12752 |
PhD Boštjan Podobnik |
Physics |
Researcher |
2014 - 2017 |
62 |
| 14. |
25463 |
PhD Tomaž Požar |
Manufacturing technologies and systems |
Researcher |
2017 |
146 |
| 15. |
27678 |
PhD Dejan Škrabelj |
Physics |
Researcher |
2014 - 2017 |
13 |
Organisations (4)
Abstract
A new type of hybrid laser with direct amplification of laser pulses with duration in the range of a few ps and a maximum output power of about 100 W will be developed in the framework of the project. One of the key advantages is that the laser will operate without complex systems, which are based on stretching and compressing of the laser pulse. In this way it will be possible to achieve significant simplification of such a system with respect to existing solutions. Laser will be based on commercial oscillator that operates on the principle of phase locking, and within the project developed fully integrated fiber amplifier with ultra-short active fibers and solid state power amplifier, which will be realized with free space optics. In this way it will be possible to combine two technologies: fiber laser, which enables simple design and great robustness and solid state amplifier which provides high output peak power. Key innovations in these studies are related to the development of:
· new pump source based on CW fiber lasers with very brightness for pumping both the fiber amplifiers and for the output solid state amplifier.
· Fully integrated two-stage amplifier based on ultra-short active fibers that will serve to seed the output solid state amplifier. Fiber amplifier will be based on active optical fiber LMA with a high doping level.
· output solid state amplifier with high output power and high amplification that will allow direct seeding with a fully integrated two-stage fiber amplifier.
Pump laser, which will be developed within the project will be fiber laser fully integrated into a single optical fiber of simple design. It will be based on a new type of active optical fiber. It is an optical fiber doped with active Yb ions, and co-doped with Sm, which will also be developed within the project. Such a fiber will due to co-doping with Sm, enable the operation of the laser at a wavelength near 970 nm. The high quality of the output beam (single-mode or quasi single-mode output) will allow achieving high brightness of the output light, which will be at least 30-100 times higher than the existing pumping solutions, which are based on laser diodes (the diameter of the beam 105μm/NA = 0.12).
The main advantages of the fully integrated two-stage amplifier based on the ultra-short active fiber will be in the use of the LMA active fibers with high doping with active Yb ions and in the direct pumping of the core. High active ions doping means high absorption of the pumping light (more than 3000dB /m at wavelength near 970 nm) and consequently high amplification per unit length. In general the peak power in fiber lasers is limited by non-linear phenomena that are directly dependent on the length and fiber cross-section. Small length of the amplifying fiber is therefore essential to achieve high peak power in fiber lasers. As the pumping system a CW fiber laser will be used having high brightness and single-mode output. It will be developed within the project. So, instead of the standard coupling of the light into the first cladding of the LMA fiber, the pump light can be coupled directly into the core of the active fiber. In this way, the overlap between pumping light and the signal laser light. Due to the increased overlap of the core and pump light the absorption of the pump light will increase, which will significantly reduce the necessary length (in range of 10 cm) of the fiber amplifier, thereby increasing the output peak power .
An important new feature will also be the output stage based on solid state amplifier, which will be pumped with a pumping system with high brightness, allowing simple design of the output amplifier stage. With high brightness it will be possible to achieve a high degree of population inversion in the active medium and consequently a high amplification also at higher average output power. So it will be possible to pump the output stage directly from the fiber amplifier, whi
Significance for science
Within the project, we report on results that have a great usable value both for the development of new laser systems and for investigating the effects occurring in optical fibers when guiding ultrashort high power laser pulses. During the research, the results of heating study of core pumped active fiber caused by photo darkening were published. The influence of photo darkening is of great importance to the scientific community because it has been in recent years identified as one of the main causes of the deterioration of the laser beam shape and its stability in high-power fiber lasers. The published model and measurement method are thus an important tool for the further development of the research field. Further, an important results are the publications of project group members dealing with an innovative way of controlling the amplitude of train pulse from fiber amplifiers, control of the gain fluctuations in the two stage amplifier when producing pulses on demand, and the control of the enhanced spontaneous emission at low repetitions and advanced driving of the seed diode. Published findings have the potential to develop more efficient lasers with a wide range of operations. An example is the generation of laser pulse trains for which modern research suggests that have positive effects on the quality of laser processing. In order to achieve this, the input pulses must be properly shaped to compensate for the gain saturation in all the amplification stages. The published article reports on theoretical model that allows for compensation in multi-amplifier systems. This eliminates the need for an active feedback loop and the simplification of the laser system. An important impact of the research are the findings on how the produced ps laser beam effects the processing quality. Using the acousto-optical modulator for positioning the laser beam on the pattern and strong focusing, micrometer structures with nanometer resolution were created. During the laser development and testing of its processing capabilities, it was found that it is necessary to consider the synchronization between the laser and the processing system. This could be done by laser system producing pulses on demand. The synchronization of laser pulses with the duration from picoseconds to several nanoseconds is a very important topic for laser applications, which was reflected in two invited lectures at international conferences. During the research of the hybrid picosecond laser, the completed project performed research work on important topics of laser development and processing.
Significance for the country
The project was realized with the involvement of three high-tech Slovene companies: two Slovenian manufacturers of laser systems (LPKF, Fotona) and Optacore, which develops and manufactures equipment for the production of active optical fibers. The project content and then the realization was in line with their real needs and interests. The project was the basis for long-term and in-depth cooperation between the actors in the field of key enabling technology Photonics and the faster integration of Slovenian researchers into the international research sphere in the rapidly developing field of new picosecond high-power laser sources. Researchers, engineers from industry and university as well as students from master and doctoral studies were closely involved in the project work. This kind of cooperation represents an important way to transfer knowledge from research institutions to industry and is also important for educating new engineers and strengthening the economy. The results and technological solutions obtained during the project have the ability to positively influence the new products development of companies and thus to the expansion of the existing market. Implementation of solutions acquired during the project into the development process of the enterprises will have a major impact on increasing competitiveness and, consequently, increasing the export share of each partner, thus creating new jobs. Above all, the results of the project are expected to have a positive effect on the strengthening of the competence of companies and the employability of future graduates and doctoral candidates from the technical and natural sciences fields.
Most important scientific results
Annual report
2015,
final report
Most important socioeconomically and culturally relevant results
Final report
