Improved omnidirectional reflectors in chalcogenide glass and polymer by using the silver doping technique

Abstract

We describe the fabrication and characterization of omnidirectional reflectors based on silver-doped chalcogenide glass and polymer. We deposited periodically alternating layers of thermally evaporated Ge33As12Se55 chalcogenide glass, sputtered silver, and spun-cast polyamide-imide polymer. The silver was subsequently dissolved into each adjacent chalcogenide glass layer, either by exposing the multilayer to visible light (photodoping) or by heating the sample. The resultant silver concentration within the chalcogenide glass layers is estimated to be ~20 at. %. Silver doping red-shifts the band edge of the glass, and produces an increase of ~0.3-0.4 in the refractive index. The glass retains good transparency in the near infrared after doping, and the technique enables the omnidirectional bandwidth to be increased from ~100 nm to ~200 nm in the 1550 nm wavelength region.

Giant field localization in 2-D photonic crystal cavities with defect resonances: Bringing nonlinear optics to the W/cm2 level

“…16-18, for example. One way to avoid leakage might be to grow a multilayer omnidirectional reflector 27 on the top and on the bottom of the slab along the y-direction, for example. We may also expect that in the future more mature fabrication techniques will be available, allowing the deep perforation of the slab for many wavelengths which would therefore avoid once and for all the problem of out of plane leakage.…”

Pulsed laser deposited amorphous chalcogenide and alumino-silicate thin films and their multilayered structures for photonic applications

“…Due to their suitable properties, amorphous chalcogenide multilayer stacks themselves or combined with low refractive index materials can satisfy mentioned criteria when designing omnidirectional mirrors for infrared region of the spectra. To date, several groups have reported attempts of multilayer stacks fabrication for omnidirectional reflection exploiting combination of a chalcogenide with a polymer [1,2,4,5], or with a fluoride [6][7][8], or combination of two amorphous chalcogenides [9][10][11][12]. It should be noted that other material combinations (requiring usually high-temperature or sophisticated processing) were already proposed, for example Si/SiO 2 [13], SiO 2 /TiO 2 [14], AlInN/GaN [15], etc.…”

“…In principle, depicted multilayered structures can be generally obtained by different thin films deposition techniques as metal-organic vapor phase epitaxy [15], sol-gel [14,16], radio frequency sputtering [13], thermal evaporation or spin coating/thermal evaporation [4,5,[8][9][10][11][12]. We already reported pulsed laser deposition (PLD) as a thin films fabrication technique viable for the amorphous chalcogenides as well as alumino-silicates being advantageous due to its simplicity, easy control of the process, often stoichiometric transfer of target material to the films, and possibility to fabricate multilayered structures [17][18][19][20].…”

Planar Quarter Wave Stack Reflectors Prepared from Chalcogenide Ge-Se and Polymer Polystyrene Thin Films

“…Recent development also showed a possibility of a low temperature fabrication of QWS devices from chalcogenide and polymer films. Chalcogenide glasses and organic polymers seem to be a good alternative to the above-mentioned dielectric materials and deposition methods because they require processing at temperatures below T < 200°C, offer a sufficiently high refractive index difference and also exhibit favourable mechanical properties, see already published results (Fink et al, 1998;Decorby et al, 2005;Clement et al, 2006;Kohoutek T. et al, 2007;Abouraddy et al, 2007 andKohoutek T. et al, 2008 a . As shown in the literature (Decorby et al, 2005 andAbouraddy et al, 2007), the omnidirectional QWS devices can be fabricated as planar or scrolled multilayers using thermal evaporation (TE) of high index As-Ge-Se or As-Se chalcogenide glasses and the spin-coating (SC) of PAI or PES polymers which form a low index films.…”