The Laser and Fiber Electronics Group at the Wroclaw University of Science and Technology, Poland is at the forefront of fiber laser technology and laser spectroscopy of gases. With a strong emphasis on both fundamental science and real-world applications, the group explores a wide range of nonlinear optical processes and frequency conversion techniques. Their interdisciplinary approach merges photonics and materials science, paving the way for next-generation laser systems, precision measurement methodologies and developing our understanding of light-matter interactions
The primary research objective is to harness nonlinear crystals for highly efficient frequency conversion, enabling tuneable and coherent light sources for high-resolution laser spectroscopy and biomedical imaging. By employing techniques such as second-harmonic generation (SHG), difference frequency generation (DFG) and optical parametric oscillation (OPO) tunable, coherent light sources can be generated. The mid-infrared region is particularly significant as it coincides with vibrational modes of many molecular species, enabling highly sensitive and precise molecular analysis. On the other hand, the generation of visible wavelengths is vital for biomedical imaging applications such as imaging of the human retina. This research is vital for the development of next-generation photonics devices and methodologies used in environmental and biomedical imaging applications
The Use of Covesion PPLN Technology
The production of high-quality fiber lasers and precise laser spectroscopy systems require reliable and efficient frequency conversion solutions. Covesion’s SHG and DFG nonlinear crystals were chosen due to their excellent phase-matching properties, high optical quality, and robust performance in frequency conversion applications.
Covesion’s SHG crystals, designed for 1064nm and 1550nm pump wavelengths, were used to convert pump pulses from dissipative soliton resonance fiber lasers, which generate microjoule-level pulses. The SHG process allowed access to higher-frequency components with improved power efficiency, significantly benefiting the investigations into nonlinear optical effects and laser pulse shaping. The availability of different crystal lengths enabled the optimization of conversion efficiency and tailored the output to specific experimental conditions.
Covesion’s DFG crystals for mixing 1064 nm and 1550 nm were utilized to facilitate the generation of laser beams in the 3–4 µm mid-infrared range, which was crucial for precision laser spectroscopy applications. The high conversion efficiency and optical stability of these crystals enabled the production of both pulsed and continuous-wave (CW) mid-IR light sources, which are essential for molecular spectroscopy and environmental sensing.
By using Covesion’s nonlinear crystals, the Laser and Fiber Electronics Group successfully enhanced their ability to perform efficient and controlled nonlinear frequency conversion. The crystals’ broad phase-matching capability, high damage threshold, and consistent performance across various experimental conditions made them indispensable. Their reliability allowed the research to focus on fundamental laser physics and spectroscopy without concerns about material degradation or inefficiency. The quality and performance of Covesion’s products have directly contributed to the success of the experimental work and played a critical role in advancing the research, enabling the development of novel mid-IR laser sources and improving the precision of the spectroscopic measurements.
Why Covesion
“Covesion’s customer service was highly responsive and technically knowledgeable, offering expert guidance on phase-matching conditions, crystal selection, and performance optimisation. Their support ensured seamless integration into our experiments, allowing us to focus on groundbreaking research with confidence.”
— Dr. Karol Krzempek, Associate Professor, Wroclaw University of Science and Technology
References
- P. Bojęś, P. Jaworski and K. Krzempek, "Nonlinear Frequency Conversion of Dissipative Soliton Resonance Pulses Using the Second Harmonic Generation Effect," in IEEE Photonics Journal, vol. 16, no. 6, pp. 1-8, Dec. 2024, Art no. 1502708, doi: 10.1109/JPHOT.2024.3477718. keywords: {Measurement by laser beam;Optical fiber dispersion;Laser beams;Optical fiber polarization;Optical fiber amplifiers;Frequency conversion;Optical variables measurement;Optical pulses;Optical fiber couplers;Erbium-doped fiber lasers;Dissipative soliton resonance;second harmonic generation;mode-locking},
- P. Bojęś, P. Jaworski, and K. Krzempek, "Synchronization of Dissipative Soliton Resonance Lasers via Cascaded Cross-Phase and Cross-Absorption Modulation for Mid-infrared Mode-locked Pulse Generation," in Laser Congress 2024 (ASSL, LAC, LS&C) , Technical Digest Series (Optica Publishing Group, 2024), paper JW2A.1.
