Parametric generation and characterization of femtosecond mid-infrared pulses in ZnGeP.

Ultrafast mid-infrared (IR) coherent radiation plays an important role in strong-field physics, wherein the use of longer wavelengths has reduced the optical intensities needed to drive light-matter interactions by orders of magnitude in comparison to near-IR radiation. Optimizing parametric interactions for generation and characterization of mid-IR pulses is an enabling step for those applications. We report on the production of >50 µJ femtosecond pulses centered at 5 µm in a two-stage optical parametric amplifier (OPA) based on ZnGeP, a high-performance optical material in this spectral region.

Nondegenerate parametric generation of 2.2-mJ, few-cycle 2.05-μm pulses using a mixed phase matching scheme.

We describe the production of 2.2-mJ, ∼6 optical-cycle-long mid-infrared laser pulses with a carrier wavelength of 2.05 μm in a two-stage β-BaB2O4 nondegenerate optical parametric amplifier design with a mixed phase matching scheme, which is pumped by a standard Ti:sapphire chirped-pulse amplification system.

Efficient generation of backward terahertz pulses from multiperiod periodically poled lithium niobate.

Backward terahertz pulses were converted from ultrafast pulses of a laser amplifier within multiperiod periodically poled LiNbO3 (PPLN) wafers. The average output powers of more than 2 microW were obtained from all six domain periods, corresponding to the frequency range of 217 GHz-2.373 THz.

Watt-level single-frequency tunable Nd:YLF/periodically poled KTiOPO(4) red laser.

Intracavity second-harmonic generation of a diode-pumped Nd:YLiF(4) ring laser oscillating on the sigma-polarized (4)F(3/2) - (4)I(13/2) transition (lambda(omega) ~ 1314 nm) with a temperature-tuned periodically poled KTiOPO(4) (ppKTP) crystal is reported, yielding up to 0.92 W tunable (lambda(2omega) = 656-658 nm) single-frequency output. Evidence of self-mode-locking via cascading nonlinearities is observed when the ppKTP is strongly phase mismatched.

[Study on two-photon induced fluorescence of newly synthesized chromophore BECVN and BMABN].

One-photon fluorescence(OPF) and two-photon fluorescence (TPF) of two chromophores 1,4-bis(9-ethyl-vinyl carbazole) naphthalene (abbreviated as BECVN) and 1,4-bis(4-N, N-methylamino styryl) naphthalene (abbreviated as BMABN) were resported. Strong emission at 492-541 nm and at 500-556 nm, respectively, were obtained under the excitation of -370 nm (Xe lamp) and of 730-800 nm femto-second laser pulses, respectively. Although the relative fluorescence quantum yield (phi(f)) of BECVN is as high as 7.

Triaryl boron-based A-pi-A vs triaryl nitrogen-based D-pi-D quadrupolar compounds for single- and two-photon excited fluorescence.

Three new A-pi-A-type compounds with trivalent boron, protected by two mesityl groups, as electron acceptor have been synthesized and investigated together with their two diphenylamino-ended D-pi-D analogues. These boranes exhibit large two-photon absorption cross sections and high fluorescence quantum yields.