We present QSFit, a new software package to automatically perform the analysis of Active Galactic Nuclei (AGN) optical spectra. The software provides luminosity estimates for the AGN continuum, the Balmer continuum, both optical and UV iron blended complex, host galaxy and emission lines, as well as width, velocity offset and equivalent width of 20 emission lines. Improving on a number of previ...

A synthetic spectrum of red sprites due to electron energization by the electric field from lighming is computed by using the electron energy spectrum obtained from a Fokker-Planck code, which includes various inelastic losses. The results are compared with observed sprite spectra. Implications to models of red sprites are presented.

Vision towards establishing an all fiber configuration is the motivation behind this work. With the increasing need for high capacity communication systems, Broadband sources have become a necessity. Broadband optical sources are an integral part of multichannel high speed fiber optical communication networks based on all-optical WDM and OCDM. FWM (Four-Wave Mixing) effects and SC (Super Contin...

We introduce a novel laser synthesizer with a simple configuration that contains no phase lock loop. This laser synthesizer generates an optical beat signal by modulating a CW light using a phase modulator and selecting two line spectra from modulation sidebands using serially-connected fiber Bragg gratings. With this configuration, the optical beat signal is obtained from a single laser source...

Optical absorption is closely associated with many physiological important parameters, such as the concentration and oxygen saturation of hemoglobin, and it can be used to quantify the concentrations of nonfluorescent molecules. We propose a method to use acoustic spectra of photoacoustic signals to quantify the absolute optical absorption. This method is self-calibrating and thus insensitive t...

We calculate the optical and Raman response within a phenomenological model of fermion quasiparticles coupled to nearly critical collective modes. We find that, whereas critical scaling properties might be masked in optical spectra due to charge conservation, distinct critical signatures of charge and spin fluctuations can be detected in Raman spectra exploiting specific symmetry properties. We...

The transmission and dielectric spectra of ferroelectric STO/PT superlattice on Si substrate under simultaneous external optical and electric field were investigated and compared at room temperature. Results found that when with an optical field, the electric field realized an effective modulation on the transmission, which displayed a diode property. In addition, a comprehensive model combined...

The optical conductivities of graphene layers are strongly dependent on their stacking orders. Our first-principle calculations show that, while the optical conductivities of single-layer graphene (SLG) and bilayer graphene (BLG) with Bernal stacking are almost frequency-independent in the visible region, the optical conductivity of twisted bilayer graphene (TBG) is frequency-dependent, giving ...

We explore how the Jaynes-Cummings ladder transpires in the emitted spectra of a twolevel system in strong coupling with a single mode of light. We focus on the case of very strong coupling, that would be achieved with systems of exceedingly good quality (very long lifetimes for both the emitter and the cavity). We consider the incoherent regime of excitation, that is realized with semiconducto...

Using the time domain master equation for a complex electric-field pulse envelope, we find analytical results for the optical spectra of passively mode-locked semiconductor lasers. The analysis includes the effect of optical nonlinearity of semiconductor lasers, which is characterized by a slow saturable amplifier and absorber. Group velocity dispersion, bandwidth limiting, and self-phase modul...