Inhibition of linear absorption in opaque materials using phase-locked harmonic generation.

We theoretically predict and experimentally demonstrate inhibition of linear absorption for phase and group velocity mismatched second- and third-harmonic generation in strongly absorbing materials, GaAs, in particular, at frequencies above the absorption edge. A 100-fs pump pulse tuned to 1300 nm generates 650 and 435 nm second- and third-harmonic pulses that propagate across a 450-microm-thick GaAs substrate without being absorbed. We attribute this to a phase-locking mechanism that causes the pump to trap the harmonics and to impress on them its dispersive properties.

[1]  N. Bloembergen,et al.  Interactions between light waves in a nonlinear dielectric , 1962 .

[2]  M. Martinelli,et al.  Measurement of Refractive Nonlinearities in GaAs Above Bandgap Energy. , 2000, Applied optics.

[3]  A. Becker,et al.  Third-harmonic generation and self-channeling in air using high-power femtosecond laser pulses. , 2002, Physical review letters.

[4]  J. M. Chamberlain,et al.  Conversion of short optical pulses to terahertz radiation in a nonlinear medium: Experiment and theory , 2007 .

[5]  C. Peters,et al.  Generation of optical harmonics , 1961 .

[6]  Second-harmonic generation pulse splitting in quartz observed by frequency-domain interferometry , 2004 .

[7]  F. Wise,et al.  Induced group-velocity dispersion in phase-mismatched second-harmonic generation , 2006 .

[8]  R. W. Terhune,et al.  Effects of Dispersion and Focusing on the Production of Optical Harmonics , 1962 .

[9]  J. Manassah,et al.  Induced phase modulation of a generated second-harmonic signal. , 1987, Optics letters.

[10]  Andrew G. Glen,et al.  APPL , 2001 .

[11]  S. L. Shapiro,et al.  SECOND HARMONIC GENERATION IN LiNbO3 BY PICOSECOND PULSES , 1968 .

[12]  Enhancement of third-harmonic generation in absorbing media , 2002 .

[13]  Nicolaas Bloembergen,et al.  Light waves at the boundary of nonlinear media , 1962 .

[14]  J. Rams,et al.  Second harmonic generation in the strong absorption regime , 2000 .

[15]  W. Glenn,et al.  Second-harmonic generation by picosecond optical pulses , 1969 .

[16]  N. Bloembergen,et al.  Dispersion of the Optical Nonlinearity in Semiconductors , 1965 .

[17]  A. Ivanov,et al.  Second-harmonic generation under phase-velocity and group-velocity mismatch:influence of cascading self-phase and cross-phase modulation. , 1997, Optics letters.

[18]  Michael E. Crenshaw,et al.  A beam propagation method that handles reflections , 1994 .

[19]  W. K. Burns,et al.  Third-Harmonic Generation in Absorbing Media of Cubic or Isotropic Symmetry , 1971 .

[20]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[21]  Olga G. Kosareva,et al.  Role of phase matching in pulsed second-harmonic generation: Walk-off and phase-locked twin pulses in negative-index media , 2007 .

[22]  J. Giordmaine,et al.  Mixing of Light Beams in Crystals , 1962 .

[23]  E. M. Lifshitz,et al.  Electrodynamics of continuous media , 1961 .