Laser acceleration of electrons in laser fields of intensities above
1028 W/cm2 were found to be in the same range as
acceleration at the surface of black holes, where the laser intensities
are in the range of pair production in vacuum due to vacuum polarization.
The results in connection with the black holes arrived at similarities to
the Hawking and Unruh radiation. We present here results based on the
thermodynamics of the vacuum fluctuations that there is a difference
between Hawking and Unruh effects in connection with the Casimir effect in
view of the vacuum properties for laser produced pairs in a vacuum.
