Status report on the Stanford Mark III infrared free electron laser

We review recent experimental results from the Stanford Mark III infrared FEL. More than 900 h of lasing operation have achieved from 2.0 to 5.5 μm and continuous gap tuning has been achieved over the design range of 1.7:1. Micropulses with peak powers as high as 2 MW and pulse lengths as short as 500 fs have been measured. A multiple output coupler arrangement has been tested which allows variation of the output coupling from 0.1% to 7% in a matter of a few minutes. Accelerator performance will also be discussed and the results of recent improvements to the microwave gun will be presented. The measured brightness of this gun is in excess of 1012 A/cm2 which is sufficient for operation in the UV.