Two pulses waltzing in a laser cavity: exploiting the fs laser as the ultimate sensor (Prof. J.-C. Diels)
- Datum: 15.06.2015
- Uhrzeit: 13:30 - 15:30
- Vortragende(r): Professor Jean-Claude Diels, University of New Mexico, Albuquerque, New Mexico
- Raum: Herbert Walther Lecture Hall
- Gastgeber: MPQ, Attosecond Physics Division
A passive interferometer such as a Michelson measures phase differences
by converting them into an amplitude modulation. By contrast, in the
Intracavity Phase Interferometer, a minute phase shift is converted into
a frequency. The technique is to use a mode-locked laser as a
differential interferometer between two frequency combs issued from the
same cavity. Measurements of phase with a sensitivity of 1:108 has been
demonstrated with an un-stabilized laser. This exquisite phase
sensitivity leads to measurements of displacements, linear and nonlinear
indices, magnetic fields, inertial measurements with unprecedented
sensitivity. Implementation with various mode-locked lasers (dye,
Ti:sapphire, optical parametric oscillators, fiber lasers) will be
presented. In these various applications, the sensor properties is
related to the phase velocities, while the envelope velocity is
maintained. The envelope velocity of a pulse is not just defined by
dispersive properties of a material or group index dk/dΩ in a medium
with saturable gain or absorption. Therefore, the label “fast light”
enhancement given to the amplification of the phase response by
Intracavity dispersion control is a misnomer, as the phase response and
its enhancement are related to phase velocities.