Phasing N longitudinal cavity modes coherently produces a pulse train of duration ~1/(NΔν), down to femtoseconds in Ti:sapphire. Active mode-locking uses an intra-cavity modulator; passive uses a saturable absorber or Kerr lens.
Phasing N longitudinal cavity modes coherently produces a pulse train of duration ~1/(NΔν), down to femtoseconds in Ti:sapphire. Active mode-locking uses an intra-cavity modulator; passive uses a saturable absorber or Kerr lens.