Measurement of the refractive index dispersion of As2Se3 bulk glass and thin films prior to and after laser irradiation and annealing using prism coupling in the near- and mid-infrared spectral range.

The prism coupling technique has been utilized to measure the refractive index in the near- and mid-IR spectral region of chalcogenide glasses in bulk and thin film form. A commercial system (Metricon model 2010) has been modified with additional laser sources, detectors, and a new GaP prism to allow the measurement of refractive index dispersion over the 1.5-10.

Integrated chalcogenide waveguide resonators for mid-IR sensing: leveraging material properties to meet fabrication challenges.

In this paper, attributes of chalcogenide glass (ChG) based integrated devices are discussed in detail, including origins of optical loss and processing steps used to reduce their contributions to optical component performance. Specifically, efforts to reduce loss and tailor optical characteristics of planar devices utilizing solution-based glass processing and thermal reflow techniques are presented and their results quantified. Post-fabrication trimming techniques based on the intrinsic photosensitivity of the chalcogenide glass are exploited to compensate for fabrication imperfections of ring resonators.

Resonant cavity-enhanced photosensitivity in As2S3 chalcogenide glass at 1550 nm telecommunication wavelength.

We report the first (to our knowledge) experimental observation of resonant cavity-enhanced photosensitivity in As(2)S(3) chalcogenide glass film at 1550 nm telecommunication wavelength. The measured photosensitivity threshold is <0.1 GW/cm(2), and a photoinduced refractive index increase as large as 0.

Optical loss reduction in high-index-contrast chalcogenide glass waveguides via thermal reflow.

A thermal reflow technique is applied to high-index-contrast, sub-micron waveguides in As(2)S(3) chalcogenide glass to reduce the sidewall roughness and associated optical scattering loss. We show that the reflow process effectively decreases sidewall roughness of chalcogenide glass waveguides. A kinetic model is presented to quantitatively explain the sidewall roughness evolution during thermal reflow.

Femtosecond laser photo-response of Ge23Sb7S70 films.

Ternary chalcogenide glass films from identical parent bulk glasses were prepared by thermal evaporation (TE) and pulsed laser deposition (PLD) and subjected to 810-nm femtosecond laser exposure at both kHz and MHz repetition rates. The exposure-induced modification on the glass film's surface profile, refractive index, and structural properties were shown to be a function of laser irradiance, the number of laser pulses per focal spot, and repetition rate. Film response was shown to be related to deposition technique-related density and the number of glass bonds within the irradiated focal volume.