In 2018, Artemis
will be undergoing a major upgrade. We will be moving the facility across the campus to new, larger, labs in the Research Complex at Harwell
, adding a new 100 kHz laser system (a joint purchase with Ultra
) and a new XUV beamline.
The new laser will use OPCPA
technology to provide mid-infrared femtosecond pulses at 100 kHz repetition rate. For Artemis, the mid-infrared will enable the generation of higher photon energy XUV pulses and the higher repetition rate allows smaller samples to be studied. For Ultra, the appeal is the ability to provide broader spectral coverage at high repetition rates, for faster data acquisition, and more efficient generation of mid- to far-IR pulses.
The smaller of the two labs will hold two laser systems, while the larger lab will hold three parallel XUV beamlines, and IR spectroscopy stations for Ultra. A custom-built external plant room will hold chillers, cryo-compressors and backing pumps to provide a low noise working environment.
100 kHz IR laser
The new laser system is a 100 kHz OPCPA system from Fastlite. The system has several outputs: 170 µJ at 1700 nm and 60 µJ at 3000 nm in < 50 fs pulses at fixed wavelengths for HHG, as well as a rapidly tuneable mode with slightly lower energy, which is more suitable for IR spectroscopy experiments. The laser system is pumped by a 200 W Yb:YAG system from Trumpf Scientific, based on an industrial micro-machining system.
The existing Artemis 1 kHz RedDragon laser
will be upgraded with a third amplifier stage to provide 2 x 9 mJ pulses. This will enable us to offer HHG with second or third harmonic drive in conjunction with tuneable outputs from the Topas OPA system, or to further amplify the output of the OPA or hollow fibre.
The new 100 kHz IR OPCPA system.
A new XUV beamline will be built for the 100 kHz laser system. The time-resolved ARPES
experiments will be the first to move to this new beamline.
IR spectroscopy stations
Ultra will develop IR spectroscopy stations, to allow us to initially evaluate the performance of the stable, broadband mid-IR (> 4 µm) output of the new system. As well as the appeal of using such a source for ultrafast IR spectroscopy, the narrowband (~ 20 cm-1) pump laser opens up new opportunities in ultrafast Raman and unique hybrid narrowband/broadband capability, such as surface sum frequency generation and multidimensional spectroscopy techniques (e.g. electronic-vibrational-vibrational).
Building work in the new labs is under way and the 100 kHz laser system is nearing completion. The newly expanded Artemis team
have completed final user experiments in the old labs, and are working to upgrade the current 1 kHz laser source and end-stations and to design the new 100 kHz HHG source, OPAs and beamline.