Advancing the state of the art in pulsed laser technology
DiPOLE laser cryogenic cooling system
CALTA is developing pulsed laser sources with both high pulse energy and high repetition rate.
Current state-of-the-art laser systems such as Vulcan, produce high energies in each pulse but are limited to repetition rates in the order of pulses per hour. Other systems can produce many pulses per second, but only at relatively low energy levels.
CALTA scientists are developing a new laser called DiPOLE, which has already delivered 10 J pulses at a 10 Hz repetition rate. The current development path involves 100 J at 10 Hz as the next step, and then 1 kJ 10 Hz.
DiPOLE amplifier head
DiPOLE is a Diode-Pumped Solid-State Laser (DPSSL), which uses laser diodes to provide the energy for its ~10 ns pulses. The gain medium is Ytterbium-doped Yttrium-Aluminium-Garnet (Yb-YAG), cooled to around 175 K, in the form of slabs which can be cooled from both sides. It is this arrangement which makes DiPOLE scalable from the current 10 J performance up to the kJ level which is our ultimate aim.
DiPOLE uses diode lasers as a pump and has an optical to optical efficiency of 25%. DiPOLE has demonstrated frequency doubling with conversion efficiency around 65%. Pulse shaping is possible.
S Banerjee et al, Temperature dependent emission and absorption cross section of Yb3+ doped yttrium lanthanum oxide (YLO) ceramic and its application in diode pumped amplifier, Optics Express 21 A726 (2013). DOI: 10.1364/OE.21.00A726 (link opens in a new window)
S Banerjee et al, High-efficiency 10 J diode pumped cryogenic gas cooled Yb:YAG multislab amplifier, Optics Letters 37 2175 (2012). DOI: 10.1364/OL.37.002175 (link opens in a new window)
K. Ertel, S. Banerjee, P. D. Mason, P. J. Phillips, M. Siebold, C. Hernandez-Gomez, and J. C. Collier, Optimising the efficiency of pulsed diode pumped Yb:YAG laser amplifiers for ns pulse generation, Opt. Express 19, 26610-26626 (2011). DOI: 10.1364/OE.026610 (link opens in a new window)
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