New diode lasers with leaking emission in an optical cavity

Abstract

We recast the study of a closed string gas in a toroidal container in the physical situation in which the single string density of states is independent of the volume because energy density is very high. This includes the gas for the well known Brandenberger-Vafa cosmological scenario. We describe the gas in the grand canonical and microcanonical ensembles. In the microcanonical description, we find a result that clearly confronts the Brandenberger-Vafa calculation to get the specific heat of the system. The important point is that we use the same approach to the problem but a different regularization. By the way, we show that, in the complex temperature formalism, at the Hagedorn singularity, the analytic structure obtained from the so-called F-representation of the free energy coincides with the one computed using the S-representation.

Simple and high performance DFB laser based on dye-doped nanocomposite volume gratings

“…Irregularities in the intensity distribution can be explained with a relatively low optical quality of the substrates. The beam divergence of this DFB laser was found to be as large as ~5 mrad which is comparable to that obtained for semiconductor leaky-mode lasers, see for example [37,38].…”

A Stable Numerical Algorithm for Investigating the Properties of Two-Dimensional Laser Waveguides in Multilayer Quantum-Dimensional Semiconductor Heterostructures

“…be a system of fundamental functions of equation (7). Then, due to the periodicity of the differential equation…”

“…Thus, the ultrasmall thickness of the layers in combination with a large number of interfaces between the layers and the alternation of layers of different materials leads to the appearance of multilayer nanostructures with unique structural features that are not present in the materials that make up the nanostructures in massive samples [1]. The manifestation of such features is associated with the detection of such physical properties in multilayer nanostructures as extremely high hardness [2], low transverse thermal conductivity [3], the effect of giant magnetoresistance (GMR) [4], divergence of the radiative characteristics of heterolasers with increasing temperature [5][6][7][8], etc.…”

“…Heteronanolasers have high radiative characteristics and different variants, for example, strained quantum-dimensional heterostructures, which are currently being actively investigated [5][6][7][8][9][10].…”

Edge-emitting InGaAs/GaAs laser with high temperature stability of wavelength and threshold current

“…It has been previously shown that it is possible to create edge-emitting lasers where just only the waveguide is involved in the lasing. For instance, in so-called leaky wave diode lasers [3,4] lasing is developed within a thin waveguide with an embedded active region (as in usual edge-emitting diode lasers), while the output emission is the emission leaking to a semiconductor substrate.…”