Water deficit and salt stress diagnosis through LED induced chlorophyll fluorescence analysis in Jatropha curcas L.

LED induced chlorophyll fluorescence analysis is employed to investigate the effect of water deficit and salt stress upon the growth process of Jatropha curcas L.. Red(Fr) and far-red(FFr) chlorophyll fluorescence around 685 nm and 735 nm, respectively, were observed and examined as a function of the stress intensity(salt concentration and water deficit).

Fourfold output power enhancement and threshold reduction through thermal effects in an Er(3+)/Yb(3+)-codoped optical fiber laser excited at 1.064 mum.

Thermally induced output power enhancement and threshold reduction in an Er(3+)/Yb(3+) -codoped optical fiber laser at 1.54mum pumped by 1.064-mu;m cw radiation is demonstrated.

Two-photon-resonant photoinduced second-harmonic generation in Er(3+)-doped germano-aluminosilicate optical fibers pumped at 1.319 microm.

The growth of a two-photon-resonant photoinduced second-harmonic signal at 660 nm in Er(3+)-doped GeO(2)-Al(2)O(3)-SiO(2) single-mode optical fibers pumped by a Nd:YAG laser at 1.319 microm is reported. Defect states in the band gap are optically excited through a resonant two-photon absorption process connecting the (4)I(15/2)-(4)F(9/2) energy levels of the erbium ions present in the fiber core.

2.3-ps pulses from a Kerr-lens mode-locked lamp-pumped Nd:YLF laser with a microdot mirror.

Pulses as short as 2.3 ps have been generated by passive mode locking of a lamp-pumped Nd:YLF laser with a microdot mirror mode locker for Kerr-lens mode-locking (KLM) saturable absorber action and a compact Gires-Tournois interferometer for dispersion compensation. KLM was initiated with an acousto-optic modulator.

Cross-phase modulation of incoherent light in single-mode optical fibers.

When two optical incoherent beams copropagate in an optical fiber, the intensity-dependent refractive index couples the two beams through a nonlinear process known as cross-phase modulation. We show, for the first time to our knowledge, experimental evidence on cross-phase-modulation-induced correlation time reduction and a concomitant growth of the frequency components of the two copropagating incoherent waves in a singlemode optical fiber. Theoretical analysis agrees well with experimental data.

Soliton generation through Raman amplification of noise bursts.

Operating in a high-gain regime, solitons with durations of the order of 600 fsec have been generated through the synchronous Raman amplification of noise bursts with durations of the order of 100psec and inverse bandwidths in the regime of the generated solitons.

Suppression and manipulation of the soliton self-frequency shift.

Direct experimental evidence is presented that shows that in the presence of bandwidth-limited amplification, specifically, stimulated Raman scattering in a single-mode silica fiber, the self-frequency-shifting effect exhibited by solitons can be effectively suppressed.

Raman amplification of modulational instability and solitary-wave formation.

The effect of synchrohous Raman gain in a single-mode fiber on a weak signal exhibiting modulational instability is shown spectrally and temporally to give rise to the rapid development of a single ultrashort solitary wave and a lowlevel dispersive pedestal.

Subpicosecond-pulse generation through cross-phase-modulation-induced modulational instability in optical fibers.

We report subpicosecond-pulse generation at 1.319 microm in a single-mode optical fiber by modulational instability induced through cross-phase modulation by 1.06-microm pulses propagating in the normal dispersion regime.

Solitons in the region of the minimum group-velocity dispersion of single-mode optical fibers.

Pulses launched with their central wavelength in the region of the minimum-dispersion wavelength of a single-mode optical fiber exhibit a distinct spectral splitting due to the nonlinearity. As a solitary wave evolves, the corresponding central wavelength of this component frequency downshifts while the dispersive wave is upshifted, in qualitative agreement with theoretical prediction.

High-efficiency single-pass solitonlike compression of Raman radiation in an optical fiber around 1.4 microm.

Highly efficient conversion (as great as 60%) into the broad first Stokes Raman band around 1.4 microm the 90-psec pump pulses from a cw mode-locked Nd:YAG laser at 1.32 microm has permitted, through a solitonlike compression mechanism in a single span of standard (lambda(0) = 1.

Cascade Raman soliton fiber ring laser.

Pulses as short as 200 fsec at 1.5 microm and 230 fsec at 1.6 microm have been generated through a cascade Raman, solitonlike process in a fiber ring oscillator.

Generation of 33-fsec pulses at 1.32 microm through a high-order soliton effect in a single-mode optical fiber.

Pulse shortening by a factor of 2700x at 1.32 microm has been realized by means of a two-stage pulse compression. In the first stage, 90-psec pulses from a cw mode-locked Nd:YAG laser were compressed to ~1.