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We present a study on amorphous SiO/SiO2 superlattice formation on Si substrate held at different elevated temperatures.

Metal island films show unique optical properties owing to the local surface plasmon resonance of islands free electrons. In the present study, the electric field assisted dissolution of clusters in metal island films is reported. Island films of Au, Ag, and Cu are deposited under different conditions by thermal evaporation and coated with thin dielectric layers. The samples are treated with the simultaneous application of an intense electric field and temperature, leading to the sample partial or total bleaching due to the dissolution of metal clusters in the films. Owing the facility of production of metal island films and the inexpensive technical requirements of the dissolution process, this approach suggests a novel path for the production of low-cost photonic structures.

Fotodinamička terapija (PDT) i fotodinamička dijagnostika (PDD) nove su metode koje se primjenjuju u liječenju određenih vrsta kožnih karcinoma, nekih drugih kožnih bolesti, te bolesti određenih unutarnjih organa. Za pobudu fotoosjetljivih tvari u bolesnim stanicama i njihov raspad pri međudjelovanju sa svjetlom, što je osnovno načelo metode, u PDT-u i PDD-u primjenjuju se izvori svjetlosti određenih valnih duljina i jakosti. Valne duljine izvora ovise o apsorcijskim karakteristikama fotoosjetljive tvari. Za aminolevuliničku kiselinu (5-ALA) u PDD-u primjenjuje se ljubičasta svjetlost, a detektira se crvena svjetlost. U PDT-u se primjenjuje crvena svjetlost. U PDD-u je potrebno odvojiti (filtrirati) uzbudni dio spektra od fluorescencije protoporfirina IX(PpIX). Za dodatnu zaštitu pacijenata i terapeuta tijekom PDD-a i PDT-a potrebno je filtrirati svjetlo u UV i u crvenom području spektra.Osnovni fizikalni problem bio je dizajn i izvedba odgovarajućih interferencijskih filtara. Dizajn filtara izveden je uz pomoć komercijalnih računalnih programa, a izradba depozicijom višeslojnih sustava dielektričnih materijala (TiO2 i SiO2). Učinjena je i karakterizacija filtara koja je potvrdila da dobiveni filtri u potpunosti odgovaraju postavljenim zahtjevima. Photodynainic therapy (PDT) and photodynamic diagnosis (PDD) are new methods in treatment of certain skin carcinoma, some other skin diseases as well as in treatments of some other internal organ carcinoma. The combination of photosensitizing drug and light, in the presence of molecular oxygene is used to obtain a therapeutic and diagnostic effects. The wavelength and intensity of the light depend on the photosensitiser used. For aminolevulinic acid (5-ALA), in PDD violet light is used while red light is detected. In PDT red light is used. In PDD the separation of excitation and absorption is needed. For additional protection of patients and therapeuts it is necessary to filtrate the light in UV and red parts of spectrum. The basic problem has been to design and produce interference filters which fulfill the above conditions. The design has been made by comercial computer programs which resulted by deposition of filters composed of multileyers of dielectric oxide materials (TiO2 and SiO2). Produced filters have been characterized and it is confirmed that they fulfill all wanted properties.

The inhomogeneities in optical films, caused by the onset of nucleation and growth of the film adjacent to amorphous glass surface, are one among numerous sources of errors in precise optical coatings production. In some recent papers it was shown that the model of the multilayer system containing a certain number of films could analyze ZrO2 films. We have used a similar modeling approach to analyze some other optical materials such as Y2O3 and CeO2. Films have been produced using a standard reactive evaporation technique. Following the measurement results, obtained by zero angle transmission and variable angle spectroscopic ellipsometry, reverse design of the monolayer with its sub-layers has been performed. A very good fit of the experimental data with the reverse designed multilayers has been obtained, showing that it is possible to find a fine substructure of analyzed films. The obtained stacks can be used then in the multilayer design process as replacement for a single film adjacent to the substrate.

The demand for very special optical coatings, having unusual optical characteristics that have no similarities with the traditional coatings, steadily increases. Typical examples are colour temperature converters, some types of narrow band reflectors, etc. A thin-film designer often encounters the very well known problem of the starting design. In this paper, a strategy of multilayer design is described. Taking an example, the target function is defined and then the complete design procedure is illustrated. The use of only two popular optical multilayer materials, namely SiO2 and TiO2 is assumed. BK7 glass and air are assumed as surrounding media. In all analysed cases, only a certain number of alternating layers can be assumed as the starting point of the design procedure. The method of global multilayer design is used in the first step, it is followed by the Tikhonravov's design method, and finally by the gradient refinement. Other possible ways and methods are discussed, and some hints are given., Zahtjevi za višeslojnim optičkim prekrivima posebnih, netradicionalnih značajki u stalnom je porastu. Primjeri su pretvarači temperature boje, uskopojasni reflektori, itd. Često smo suočeni s problemom početne strukture višesloja. Ovdje se opisuje strategija proračuna višesloja. Izabrana je proizvoljna ciljna funkcija i opisan cijeli postupak oblikovanja višesloja uz pretpostavku dvaju optičkih materijala, SiO2 i TiO2. Podloga je BK7 staklo a upadno sredstvo zrak. U prvom koraku primijenjena je metoda globalnog oblikovanja, zatim je upotrebljena Tikhonravova metoda i na kraju fina gradijentna metoda.

Ultrathin layers of noble metals obtained by deposition to the substrate during evaporation in high vacuum represent nanostructured matter. Nanoparticles showing interesting optical properties due to the localized surface plasmons are formed instead of homogenous layer. Optical properties of noble metal nanoparticles are closely related to their size, shape, distribution and dielectric environment. Localized surface plasmon properties may be tailored by changing deposition parameters (amount of material and substrate temperature) or by changing dielectric environment (dielectric layers below and/or above metal nanoparticles). The goal of research was to correlate optical and structural properties of noble metal island films. Results show that different combinations of ultrathin noble metal layers and dielectric layers have a potential for application in novel optical components. Ultrathin layers of noble metals obtained by deposition to the substrate during evaporation in high vacuum represent nanostructured matter. Nanoparticles showing interesting optical properties due to the localized surface plasmons are formed instead of homogenous layer. Optical properties of noble metal nanoparticles are closely related to their size, shape, distribution and dielectric environment. Localized surface plasmon properties may be tailored by changing deposition parameters (amount of material and substrate temperature) or by changing dielectric environment (dielectric layers below and/or above metal nanoparticles). The goal of research was to correlate optical and structural properties of noble metal island films. Results show that different combinations of ultrathin noble metal layers and dielectric layers have a potential for application in novel optical components.