• Question: Is it possible for a laser to be brighter than the sun?

    Asked by farhan010200 to Ben, Jony, Katharine, Mark, Peter on 18 Nov 2011.
    • Photo: Peter Williams

      Peter Williams answered on 15 Nov 2011:

      At Daresbury we have a laser which has an instantaneous brightness 15 (yes, fifteen) orders of magnitude brighter than the sun. It’s not continuous though – the flashes are around 1 ps (=10^-12 seconds) in duration. It’s called a free-electron laser.
      The uses for these things are not yet fully explored, but those short, bright flashes will allow us to make “real time videos” of chemical bonds rearranging themselves. This is an entirely new field of science – the dynamics of chemical and biological systems at the molecular scale.

      At Daresbury, our FEL is called ALICE (accelerators and lasers in combined experiments) and operates in the infra-red. Last year the world’s first X-ray FEL produced first light – the Linac Coherent Light Source in California. We’d really like to build one of those here too!

    • Photo: Ben Still

      Ben Still answered on 15 Nov 2011:

      I defer to Peter on this one!

    • Photo: Mark Basham

      Mark Basham answered on 15 Nov 2011:

      Don’t know about lasers (Peter knows his stuff here) But our Synchrotron Light Source generates light which is which is similar in brightness to the free electron laser, but the light we generate is slightly different and is used more like a “still camera” than the free electron lasers “video camera”

    • Photo: Katharine Schofield

      Katharine Schofield answered on 18 Nov 2011:

      I’m not a laser expert, but I asked someone who is! Ceri works at our Central Laser Facility at the Rutherford Appleton Lab in Oxfordshire. She said:
      “Here at the Central Laser Facility we have 2 of the most intense lasers in the world! If you were to take all of the sunlight shining down on earth at the moment and focus it all down, squeeze it right down, to fit on the top of a pinhead, then that would be the same intensity of light that we can achieve in a single pulse of the lasers that we have here. However, the lasers pulses only last less than a trillionth of a second so there’s no need to worry. So yes, we can easily build lasers that are brighter than the sun, even for just a teeniest fraction of a second. ”

      thanks Ceri!

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