We have developed a theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers. This theory is based on solving the resonance conditions which involve two types of reflectivities of chirped circular gratings. This approach is shown to be in agreement with previous derivations which use the characteristic equations. Utilizing this unified analysi...

We report observations of field emission from self-catalyzed GaAs nanowires grown on Si (111). The measurements were taken inside a scanning electron microscope chamber with a nano-controlled tungsten tip functioning as anode. Experimental data were analyzed in the framework of the Fowler-Nordheim theory. We demonstrate stable current up to 10-7 A emitted from the tip of single nanowire, with a...

[1] Mixing ratios and emission rates of monoterpenes were measured above a ponderosa pine plantation in the Sierra Nevada mountains before, during and after a precommercial thinning in spring 2000. The thinning removed and left onsite approximately one half of the plantations biomass. Monoterpene fluxes increased tenfold during the thinning and pinene mixing ratios in excess of 3 ppb were obser...

We show that the reduction in photon number fluctuations at laser threshold often cited as a fundamental laser property does not occur in small semiconductor lasers. The conventional theory of threshold noise is not valid in lasers with a spontaneous emission factor larger than 10. If the spontaneous emission factor is larger than 10, the photon number statistics even remain thermal far above t...

Recent studies have predicted that heterostructure superlattices can enhance the effective thermoelectric power factor significantly through selective emission of hot carriers via thermionic emission. Here, we study the potential of SiGe/Si superlattices for power generation at high temperatures. A detailed theory based on Boltzmann transport equation is developed which takes into account multi...

We present a statistical study of the Purcell enhancement of the light emission from quantum dots coupled to Anderson-localized cavities formed in disordered photonic-crystal waveguides. We measure the time-resolved light emission from both single quantum emitters coupled to Anderson-localized cavities and directly from the cavities that are fed by multiple quantum dots. Strongly inhibited and ...

A conducting reball expanding at relativistic speed into an ambient magnetic eld generates a rapidly changing electric current which emits coherent electromagnetic radiation at radio frequencies. The critical frequency (upper limit of the emission) strongly depends on the Lorentz factor of the expansion. We have searched for simultaneous radio emission in the data of solar radio spectrographs a...

The rapidly varying non-thermal X-ray emission observed from Sgr A⋆ points to particle acceleration taking place close to the supermassive black hole. The TeV γ-ray source HESS J1745−290 is coincident with Sgr A⋆ and may be closely related to the X-ray emission. Simultaneous X-ray and TeV observations are required to elucidate the relationship between these two objects. Here we report on joint ...

We propose and demonstrate a new approach for achieving enhanced light-matter interactions with quantum emitters. Our approach makes use of a plasmon resonator composed of defect-free, highly crystalline silver nanowires surrounded by patterned dielectric distributed Bragg reflectors. These resonators have an effective mode volume (V(eff)) 2 orders of magnitude below the diffraction limit and a...