Through the Lasers4EU staff exchange scheme, PhD student Huzefa Bhanpurwala completed a two-week placement at the Centre for Advanced Laser Technology and Applications (CALTA) within STFC’s Central Laser Facility. The exchange delivered significant technical benefits for ongoing and future high-power laser developments at the HiLASE Centre.
During the exchange, the visiting researcher gained first-hand experience with the development of a next-generation Ti:Sapphire amplifier, designed to deliver 10 J pulses at a 10 Hz repetition rate with 40 fs pulse duration. This exposure provided valuable insight into the design challenges of ultrafast, high-energy laser systems, including amplifier architecture, thermal management, and long-term stability considerations.
A key part of the placement focused on the pump laser system driving the Ti:Sapphire amplifier: the DiPOLE100, a 100 J cryogenically cooled Yb:YAG laser operating at a fundamental wavelength of 1030 nm and generating its second harmonic generation (SHG) at 515 nm. The exchange helped deepening the expertise in high-energy frequency conversion and nonlinear crystal selection.
The know-how acquired during the staff exchange will be directly applied at HiLASE Centre, where a similar DiPOLE100 system is already in operation. The experience gained will support improvements in SHG performance, stability, and conversion efficiency, as well as more effective handling and tuning of LBO crystals. In addition, hands-on work with large-aperture optics, including wave plates and harmonic separators, strengthened essential skills for safely handling and aligning components commonly used in high-energy laser facilities.
Overall, the staff exchange has significantly strengthened technical capabilities in ultrafast laser development, frequency conversion, and system integration. The knowledge transfer enabled by Lasers4EU will contribute not only to current project enhancements at HiLASE, but also to the long-term development of advanced laser technologies across the European laser research community.
The staff exchange at Rutherford Appleton Laboratory was a highly valuable experience that strengthened my expertise in high-energy ultrafast laser systems. I gained hands-on insight into the development of a next-generation Ti:Sapphire amplifier and practical experience with high-energy second harmonic generation using the DiPOLE100 laser and LBO crystals.
The knowledge acquired is directly applicable to my work at the HiLASE Centre, particularly in improving frequency conversion modules and handling large-aperture optics. Overall, the exchange enhanced my technical skills and reinforced international collaboration within the project.