Transient chirp in high speed photonic crystal quantum dots lasers with controlled spontaneous emission

We report on a series of experiments on the dynamics of spontaneous emission controlled nanolasers. The laser cavity is a photonic crystal slab cavity, embedding self-assembled quantum dots as gain material. The implementation of cavity electrodynamics effects increases significantly the large signal modulation bandwidth, with measured modulation speeds of the order of 10 GHz while keeping an extinction ratio of 19 dB. A linear transient wavelength shift is reported, corresponding to a chirp of less than 100 pm for a 35-ps laser pulse. We observe that the chirp characteristics are independent of the repetition rate of the laser up to 10 GHz

Calculation of atomic spontaneous emission rate in 1D finite photonic crystal with defects

We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.Comment: Cent. Eur. J. Phys, in pres

Sytuacja polsko-litewska, ani wojna, ani pokój — stan trzeci, odosobnienie

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

El objeto formal de la vis cogitativa en Santo Tomás de Aquino

According to the mind of St. Thomas Aquinas, the power of sensitive knowledge called «cogitative» may be considered in two ways. On the one hand, is the animal estimative and, as such, it apprehends the same formal object quod, namely, intentions of benefit or harm in the sensitive level. But because of its particular mode of operation, these intentions are not known by her only in order to the conservation of the human individual or species to which man belongs. The recognition of two dimensions in the cogitative power is justified in St. Thomas by the special relationship that exists between it and the universal reason. For one, the cogitative is not a different faculty from the natural estimate. For this, she apprehends necessary intentions for the perfection of human sensitive life. On the other hand, reason has a particular influence on the cogitative power that makes it operate in its own way, that is, discursively. This mobile character in the apprehension of the cogitative allows the formation of a sensory experience, under which its formal object is magnified. This becomes even more reasonable when you consider that the sensitive knowledge places the intellectual man. Thus, the cogitative not simply apprehends the individual as beneficial or detrimental to the survival of the knowing, but as a subject of a certain nature. De acuerdo a la mente de Santo Tomás de Aquino, la potencia de conocimiento sensible que se denomina «cogitativa » es susceptible de una doble consideración. Por un lado, es la estimativa animal y, como tal, aprehende su mismo objeto formal quod, esto es, las intenciones de beneficio o perjuicio a nivel sensible. Pero a causa de su particular modo de operar, esas intenciones no son conocidas por ella solamente en orden a la conservación del individuo humano o de la especie a la que él pertenece. El reconocimiento de una doble dimensión de la cogitativa está en Santo Tomás justificado por la particular relación que existe entre ella y la razón universal. Por un lado, la cogitativa no es una facultad distinta de la estimativa natural. Por esto, ella aprehende las intenciones necesarias para la perfección de la vida sensitiva humana. Por otro lado, la razón ejerce sobre la cogitativa un influjo particular que la hace operar a su modo, esto es, de manera discursiva. Este carácter móvil en la aprehensión de la cogitativa permite la conformación de una experiencia a nivel sensible, en virtud de la cual su objeto formal se ve ampliado. Esto resulta aún más razonable si se tiene en cuenta que el conocimiento sensorial del hombre prepara el intelectual. De esta manera, la cogitativa no aprehende simplemente al individuo como beneficioso o perjudicial para la subsistencia del cognoscente, sino como sujeto de una cierta naturaleza

Ostatnia Konstytucja Austrji

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

Algunas consideraciones acerca de la experiencia psicológica del tiempo en la amistad según Tomás de Aquino

For Thomas Aquinas, man's goal is the complete actualization of his potentialities, which he achieves in this life in a progressive manner as he affirms himself more and more in the plenitude of the act of being. On the other hand, Aquinas understands eternity not in the sense of an endless life but, rather, as a life that lacks temporal succession and, moreover, that possesses full actuality. Friendships founded on virtue put man in contact with this ultimate perfection because they order it to it, producing in him, to a certain extent, a psychological experience of absence of succession when he enjoys the company of a friend. The incontinent man, who acts according to the incessant movement of his passions and whose sensitivity is dulled by the succession of images, on the other hand, frequently establishes friendships founded on mere pleasure or utility. Because they are closed to true friendship, these relationships, very common in our time, cause man more suffering than pleasure, especially because they keep him subject to the uninterrupted desire for goods that never end up satisfying him, immersing him, in a certain way, in the becoming of material things.Para Tomás de Aquino la finalidad del hombre consiste en la completa actualización de sus potencialidades, que va alcanzando en esta vida de manera progresiva a medida en que va afirmándose más y más en la plenitud del acto de ser. Por otra parte, el Aquinate entiende la eternidad no en el sentido de una vida interminable sino, más bien, como una vida que carece de sucesión de temporal y que, por lo mismo, posee actualidad plena. En cuanto lo ordenan a ella, las amistades fundadas en la virtud ponen al hombre en contacto con esa perfección última, produciéndole, en alguna medida, una experiencia psicológica de ausencia de sucesión cuando gozan de la compañía del amigo. El hombre incontinente, que obra de acuerdo con el movimiento incesante de sus pasiones y que posee su sensibilidad embotada por la sucesión de imágenes, en cambio, con frecuencia establece amistades fundadas sobre el mero placer o la utilidad. En la medida en que se cierran a la verdadera amistad, esas amistades, muy comunes en nuestra época, le producen al hombre más sufrimiento que placer, en especial porque lo mantienen sujeto al deseo ininterrumpido de bienes que nunca terminan por colmarlo, sumergiéndolo, en cierto modo, en el devenir de las cosas materiales

Comparison of Tearing off and Impact Load Resistance of Selected Phosphate and Glassionomer Cements

Cements used for seating fixed dentures are expected to have some definite resistance to tearing off and impact loads. It seems that these features may significantly influence the effective adhesion of a crown or bridge. For final seating of dentures both phosphate and glassionomer cements, which are a more recent invention, are used. The aim of this work was to compare two cements from the phosphate group with two cements from the glassionomere group with respect to their tearing off resistance and resistance to impact loads. The experiment was conducted in vitro. In the test for tearing off resistance Osteoplant implant was used as the abutment. The crown was a cast chrome- nickel substructure. The Raustein FM 250 was used for registration of this phenomenon. Six tests for tearing were conducted for each cement. A special device was constructed to test resistance to impact loads. The abutment was made of brass. After coating with a layer of varnish the substructure was contoured as a wax pattern and then cast in Remanium CS alloy. This metal substructure had additional handles for easier manipulation. Six tests were made for each material. When analyzing the results we found significant differences between the values of tearing resistance of the cements from the two groups (the average tearimg resistance for 1. Harv. Phosp. 183.3 N; 2. Poscal 273.5 N; 3. Rely X 27.8 N; 4. GC Fuji I 19 N). Significant differences were also observed when impact load resistance was tested

Influencia de la dimensión afectiva en las potencias cognoscitivas para elaboración del justo medio virtuoso en Tomás de Aquino. Una reflexión a partir del conocimiento por connaturalidad afectiva

The affective influence around the elaboration of the judgment that is the product of the habit of virtue has been extensively and explicitly treated both by Saint Thomas and by his commentators, mainly by deepening the nature of virtue and the understanding of it as second nature. This same relationship has a central place in knowledge by affective connaturality, reflected in the work of Aquinate. However, only in the twentieth century there was an interest of its commentators to delve into this type of knowledge generated by inborn nature. However, this recent investigation did not stop at specifying some topics that we intend to develop in this work, namely, the degree of certainty inherent to the judgment by connaturality, the place that prudence has and the influence of passion in the articulation of the intelligence and the internal senses subordinate to it, especially the cogitative.La influencia afectiva en torno a la elaboración del juicio que es producto del hábito de la virtud ha sido amplia y explícitamente tratada tanto por santo Tomás como por sus comentadores, principalmente al profundizar la naturaleza de la virtud y la comprensión de esta como segunda naturaleza. Esta misma relación tiene un lugar central en el conocimiento por connaturalidad afectiva, reflejado en la obra del Aquinate. Sin embargo, recién en el siglo XX hubo un interés de sus comentaristas por profundizar en torno a este tipo de conocimiento generado por connaturalidad. No obstante, esta reciente indagación no se detuvo en precisar algunos tópicos que pretendemos desarrollar en este trabajo, a saber, el grado de certeza propio del juicio por connaturalidad, el lugar que tiene la prudencia y la influencia de la pasión en la articulación de la inteligencia y los sentidos internos subordinados a ella, en especial la cogitativa

Angular and Temperature Tuning of Emission from Vertical-External-Cavity Surface-Emitting Lasers (VECSELs)

In this paper we demonstrate how the tuning of the VECSEL heterostructure can be precisely determined. Since the VECSEL active region is embodied in a microcavity, the photoluminescence signal collected from the chip surface is modified by the resonance of this cavity. The angle resolved photoluminescence measurements combined with the temperature tuning of the structure allowed us to precisely determine VECSEL emission features. The investigated structure consists of GaAs cavity with six InGaAs quantum wells and is designed for lasing at 980 nm. Introduction Vertical-external-cavity surface-emitting lasers (VECSELs

Concept of Inverted Refractive-Index-Contrast Grating Mirror and Exemplary Fabrication by 3D Microprinting

Highly reflective mirrors are indispensable components in a variety of state-of-the-art photonic devices. Typically used, bulky, multi-layered distributed Bragg (DBR) reflectors are limited to lattice-matched semiconductors or nonconductive dielectrics. Here, we introduce an inverted refractive-index-contrast grating (ICG), as compact, single layer alternative to DBR. In the ICG, a subwavelength one-dimensional grating made of a low refractive index material is implemented on a high refractive index cladding. Our numerical simulations show that the ICG provides nearly total optical power reflectance for the light incident from the side of the cladding whenever the refractive index of the grating exceeds 1.75, irrespective of the refractive index of the cladding. Additionally, the ICG enables polarization discrimination and phase tuning of the reflected and transmitted light, the property not achievable with the DBR. We experimentally demonstrate a proof-of-concept ICG fabricated according to the proposed design, using the technique of 3D microprinting in which thin stripes of IP-Dip photoresist are deposited on a Si cladding. This one-step method avoids laborious and often destructive etching-based procedures for grating structuration, making it possible to implement the grating on any arbitrary cladding material