Gradient-index narrow-bandpass filter fabricated with glancing-angle deposition

Abstract

Glancing-angle deposition (GLAD) is a fabrication method capable of producing thin films with engineered nanoscale porosity variations. GLAD can be used to create optical thin-film interference filters from a single source material by modification of the film refractive index through control of film porosity. We present the effects of introducing a layer of constant low density into the center of a rugate thin-film filter fabricated with the GLAD technique. A rugate filter is characterized by a sinusoidal refractive-index profile. Embedding a layer of constant refractive index, with a thickness equal to one period of the rugate index variation, causes a narrow bandpass to appear within the filter's larger stop band. Transmittance measurements of such a gradient-index narrow-bandpass filter, formed with titanium dioxide, revealed an 83% transmittance peak at a vacuum wavelength of 522 nm, near the center of the stop band, with a FWHM bandwidth of 15 nm.

Designing Plane Wave Modulators Using 1dpc Nanostructure With R-Grin Defect Layer

“…Thanks to the modern technological advantages, realization of such distribution functions inside a material is possible. Using the modulated electrical field [21], glancing angle deposition technique [22], optical holography and interferometric methods [23] are some of them. For the cases of under study, the intensity distributions of the Gaussian, the square of the sinc and cosine, can be produced by applying an intensity distribution of the Gaussian, which is the laser radiation fundamental mode, the performance of the diffraction pattern by a single slit or double-slit interference inside a photosensitive media, respectively.…”

Artificial dispersion of all-dielectric gradient nanostructures: frequency-selective interfaces and tunneling-assisted broadband antireflection coatings

“…The smooth spatial changes of chemical components with low and high refractive indices in the nanofilms provides the spatial distributions of their refractive indices, varied at the nanometric scale; these distributions offer the potential for design of optical filters [9] and antireflection coatings [10]. The ability of gradient metamaterials to govern the propagation of electromagnetic waves on and below the wavelength scales, accompanied by low losses and weakened scattering, gives rise to the series of unusual physical effects.…”

“…Гладкие пространственные изменения химиче-ских компонентов с низким и высоким показате-лем преломления в наноплёнках обеспечивают пространственное распределение их показате-лей преломления, варьирующееся в нанометро-вом масштабе; эти распределения обеспечивают потенциал для конструирования оптических фильтров [9] и просветляющих покрытий [10]. Способность градиентных метаматериалов управлять распространением электромагнитных волн в масштабах порядка и ниже длины волны, с учётом низких потерь и слабого рассеяния, мetatronics profiles of n(z); this frequency Ω separates the spectral ranges, characterized by real and imaginary values of wave vectors in a transparent lossless nanofilm.…”

Phase Shift Defect Modes in One-Dimensional Asymmetrical Photonic Structures Consisting of Two Rugate Segments With Different Periodicities

“…Photonic crystals that are composed of one-dimensional (1D) periodic dielectric materials of continuously varying refraction index with defect modes have recently received much attention [1][2][3][4][5][6][7][8][9]. Gradient-index optical materials have been used to fabricate interference filters [1,2] and environment sensors [10], and potential applications such as broadband laser protection eyewear and spectral beam splitter have also been demonstrated [11][12][13].…”

“…Gradient-index optical materials have been used to fabricate interference filters [1,2] and environment sensors [10], and potential applications such as broadband laser protection eyewear and spectral beam splitter have also been demonstrated [11][12][13]. Many applications based on 1D photonic crystals are formed by repeating two or more distinct homogeneous dielectric layers with different refraction indices [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]; however, studies on 1D periodic dielectric structures with smoothly varying refraction index are still valuable, because of advantages such as reduced optical losses and better mechanical properties in contrast to discrete multilayer structures [13,[34][35][36][37].…”