In 1950, a quarter of a century after his first-ever nonlinear optical experiment when intensity-dependent absorption was observed in uranium-doped glass, Sergey Vavilov predicted that birefringence, dichroism and polarization rotatory power should be dependent on light intensity. It required the invention of the laser to observe the barely detectable effect of light intensity on the polarizati...

We demonstrate that the phenomenon known as Spontaneous Parametric Down Conversion is really an amplification, in a nonlinear crystal pumped by a laser, of certain pairs of modes of the electromagnetic zeropoint field. The demonstration is achieved by showing the existence of a related phenomenon, Spontaneous Parametric Up Conversion. This phenomenon, once observed, will cast doubt on the quant...

The optical/near-IR stellar continuum carries unique information about the stellar population in a galaxy, its mass function and star-formation history. Star-forming regions display rich emission-line spectra from which we can derive the dust and gas distribution, map velocity fields, metallicities and young massive stars and locate shocks and stellar winds. All this information is very useful ...

We revisit the process of optical wave thermalization through supercontinuum generation in photonic crystal fibers. We report theoretically and numerically a phenomenon of ‘truncated thermalization’: The optical wave exhibits an irreversible evolution toward a Rayleigh-Jeans thermodynamic equilibrium state characterized by a compactly supported spectral shape. This phenomenon sheds new light on...

We demonstrate theoretically and experimentally that optical beams are self-focused and self-trapped upon initiating photopolymerization. This unique nonlinear optical phenomenon is dependent on the optical exposure and produces permanent index-of-refraction changes larger than 0.04. The resulting nonlinear wave equation is shown to be nonlocal in time and displays self-trapped solutions only f...

In this work, we report, optical properties of Cd1-xSnxTe quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related t...

In this work, we report, optical properties of Cd1-xSnxTe quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (TGA) as a modifier agent. The optical characterization of the samples was performed through absorption (UV) and photoluminescence spectra (PL). A red shift absorption and fluorescent emission peaks was observed which can be related t...

Dispersion, as the characteristic variation of refractive index with wavelength, is more pronounced, where the wavelength is approaching to the absorption band. In ultra-optical glasses, the nonlinear refractive index, concerning to the light intensity dependent phenomenon, becomes considerable. Here, two ultra-optical property glass systems; TiO2-Bi2O3-PbO (TBP...