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The amorphous chalcogenide glass Sn1As20S79 is demonstrated to undergo permanent changes in refractive index on irradiation with ultraviolet light. The refractive properties of this material and the effect of annealing at temperatures below the glass transition temperature are investigated in detail. An Sn1As20S79 strip waveguide is fabricated using this photoinduced refractive index change, and the device is shown to function as expected with good propagation characteristics for the 632.8 nm guided mode. [ABSTRACT FROM AUTHOR]

Changes in the refractive index and thickness of amorphous As2S8 semiconductor film are observed under illumination, annealing–illumination, and annealing-illumination cycles. Properties of the As2S8 film are measured using techniques of prism coupler, x-ray diffraction spectra and Raman spectra. After light illumination the refractive index change in an as-deposited As2S8 film is one order of magnitude greater than that of an annealed As2S8 film, corresponding to ∼0.06 and ∼0.0057, respectively. Photoexpansions with a change in the relative film thickness of the as-deposited and annealed As2S8 film are nearly -3.5% and -2.1%, respectively, which exhibit the photodensification. The full reversibility of the photoinduced refractive index change is claimed on an annealed As2S8 film sample. [ABSTRACT FROM AUTHOR]

Optical nonlinearities in the undoped As20S80, low doped P2As20S78 and Sn1As20S79 chacogenide glasses are investigated by using Z-scan method. These experiments show that at 1064 nm the figure of merit (FOM) for As20S80 is ∼1.02, while for Sn1As20S79 increases to ∼1.42, and for P2As20S78 decreases to ∼0.83. These resulted data indicate the addition of Sn in As20S80 system chalcogenide glass can enhance FOM due to creating narrow energy gaps. In addition, the self-phase modulation (SPM) width experiment for Sn1As20S79 strip waveguide displays that the full width half maximum (FWHM) of spectral width increases approximately 0.8 nm under the induction of bandgap light, meaning that the bandgap light can induce to enhance its optical nonlinearity with the nonlinear refractive index of n2≅5.27×10−14 cm2/W. [ABSTRACT FROM AUTHOR]

Amorphous As2S8 chalcogenide glass is shown to undergo changes in the refractive index upon exposure to ultraviolet light. This phenomenon is employed to fabricate an As2S8 stripe waveguide, which is shown to be an effective guided mode device with a useful switching functionality based on the photo-optical effect. [ABSTRACT FROM AUTHOR]

Efficient inscription of Fiber Bragg gratings (FBGs) in single-mode, thin cladding As(2)S(3) fibers is demonstrated by using near bandgap light at 532 nm. The FBGs with the reflectivity of over 80% can be induced in only 80-90 s, substantially faster than in previous reports. The dynamics of the grating growth are investigated in the photosensitivity process, showing a fast blue shift of the Bragg wavelength and then a somewhat slower red shift. The aging of the grating after fabrication is also reported, indicating a 37% decay of the grating strength.