Fabrication of blue light-blocking optical interference coatings by the solgel method.

We report on the solgel method of fabrication of thin films of high optical quality and with tunable index of refraction. The resulting coatings are hard, durable and robust against humidity and common organic solvents. Bragg mirrors and edge filters have been made by stacking these films.

Linearly polarized Q-switched ceramic laser made with anisotropic nanostructured thin films.

A polarizing laser mirror was made of an alternating sequence of low and high refractive index layers of titanium oxide using glancing angle deposition (GLAD). Large refractive index contrast and large birefringence, reaching 0.5 and 0.

Compact linearly polarized ceramic laser made with anisotropic nanostructured thin films.

A novel method is proposed for the fabrication of polarizing laser mirrors for compact solid-state lasers using glancing angle deposition. Changing the inclination angle and the azimuthal orientation of the substrate during deposition allows one to create and control in-plane birefringence of a deposited thin film by changing its nanostructure. Principal refractive indices of tungsten trioxide films were determined for various deposition angles using transmission and reflection ellipsometry.

Continuously variable, electrically addressed beam splitter based on vanadium dioxide.

Vanadium dioxide (VO(2)) is used to implement an electrically addressable beam splitter with continuously variable splitting ratios. The electrical control of temperature in a thin VO(2) layer is used to vary its transmission/reflection behavior. The technique is characterized for various incidence angles, s- and p-polarizations, and the wavelength range of 400-2000 nm.

Biaxial thin-film coated-plate polarizing beam splitters.

We present a design for a biaxial thin-film coated-plate polarizing beam splitter that transmits the p-polarized component of a beam of light without change of direction and reflects the s-polarized component. The beam splitter has a periodic structure and is planned for fabrication by serial bideposition in mutually orthogonal planes. Recent experimental data for form-birefringent silicon is used to establish the feasibility of the design for a beam splitter to be used at 1310 nm and at an angle of 45 degrees in air.

Control of power law scaling in the growth of silicon nanocolumn pseudo-regular arrays deposited by glancing angle deposition.

Nanocolumn pseudo-regular arrays of silicon with controlled aspect ratio and porosity are fabricated by electron-beam evaporation using the glancing angle deposition (GLAD) method with vapour impinging at oblique incidence onto rapidly rotating substrates. The width W at positions y along the height of one individual column scales with y following a power law dependence W approximately y(p). We demonstrate that the scaling exponent value, p, can be modified from 0.

Enhanced birefringence in vacuum evaporated silicon thin films.

We report an experimental study of enhanced optical birefringence in silicon thin films on glass substrates. Form anisotropy is introduced as an atomic-scale morphological structure through dynamic control of growth geometry. The resulting birefringence is large compared with naturally anisotropic crystals and is comparable to two-dimensional photonic crystals.

Vacuum evaporated porous silicon photonic interference filters.

Porous materials with nanometer-scale structure are important in a wide variety of applications including electronics, photonics, biomedicine, and chemistry. Recent interest focuses on understanding and controlling the properties of these materials. Here we demonstrate porous silicon interference filters, deposited in vacuum with a technique that enables continuous variation of the refractive index between that of bulk silicon and that of the ambient (n approximately 3.