Thulium-Based Ceramic Amplifier for Laser Acceleration

Laser plasma accelerators (LPA) enabled by the Tm laser driver to be developed by this project offer much reduced size and cost compared to conventional accelerators of the same energy. This would drastically cut the cost of high- energy particle research on collider-based facilities and advanced light sources. Planned conventional accelerators (e.g., for the proposed International Linear Collider) would be 25 miles long. LPA hold the promise of making possible a low-cost table-top accelerator with particle energies in the tens of GeV range. The proposed 2-micron Tm laser technology offers to advance LPA of nuclear particles, thus replacing the traditional mammoth-size and costly accelerator research facilities with room-size systems. The advantages of 2-micron lasers over their more developed 0.8-micron and 1-micron counterparts is in 4 to times improved particle trapping by ponderomotive force, thus enhancing the acceleration process. Compactness and relative simplicity of laser accelerators promises to greatly reduce the cost and timelines of high-energy research, and to advance new scientific discoveries. With energetic particle affordable for universities, commercial laboratories (e.g., semiconductor material development), and hospitals, the US would be able to maintain its technological leadership. The proposed project will leverage a novel ceramic laser material that we started to investigate on an earlier DOE project, thus benefiting from previous US government investment. In Phase I, we will conduct engineering design, validation testing of materials, and fabricate a novel Tm-doped laser ceramic. In Phase II, we will fabricate and test the laser gain elements, and construct and test an amplifier section for the driver laser. An eye-safe 2 μm Tm-based EPDL (especially pulsed) also has major commercial applications ranging from laser material processing (especially cutting and welding plastics) to remote sensing, biological tissue surgery in vivo, remote sensing, lidar, infra-red countermeasures, and optical communication. In laser material processing, a 2- micron EPDL offers to supplant the 1-micron (non-eye-safe) thin disk and fiber lasers which have been the dominant technology for lasers in the kilowatt range for the last 10 years.