Figures & data
Figure 1. Ge–Sb–Se ternary diagram with the two selected compositions (GeSe2)90(Sb2Se3)10 (Ge28.1Sb6.3Se65.6, Se2) and (GeSe2)50(Sb2Se3)50 (Ge12.5Sb25Se62.5, Se6) for the bulk glass targets and the sputtered films.
![Figure 1. Ge–Sb–Se ternary diagram with the two selected compositions (GeSe2)90(Sb2Se3)10 (Ge28.1Sb6.3Se65.6, Se2) and (GeSe2)50(Sb2Se3)50 (Ge12.5Sb25Se62.5, Se6) for the bulk glass targets and the sputtered films.](/cms/asset/ea4714cc-d76d-4217-975a-d8daf6f8aa0c/yadv_a_1338211_f0001_oc.gif)
Figure 2. Chemical composition of (GeSe2)90(Sb2Se3)10 (Ge28.1Sb6.3Se65.6, Se2) and (GeSe2)50(Sb2Se3)50 (Ge12.5Sb25Se62.5, Se6) sputtered films and bulk glass targets determined by EDS analysis (±1 at.%) compared to theoretical composition.
![Figure 2. Chemical composition of (GeSe2)90(Sb2Se3)10 (Ge28.1Sb6.3Se65.6, Se2) and (GeSe2)50(Sb2Se3)50 (Ge12.5Sb25Se62.5, Se6) sputtered films and bulk glass targets determined by EDS analysis (±1 at.%) compared to theoretical composition.](/cms/asset/86f01c96-fa5e-4895-bd3b-317e4046a2e2/yadv_a_1338211_f0002_oc.gif)
Figure 3. Refractive index in near- and mid-IR (±0·01) extracted from VASE data of bulk targets and sputtered (Ge28.1Sb6.3Se65.6, Se2) and (Ge12.5Sb25Se62.5, Se6) thin films.
![Figure 3. Refractive index in near- and mid-IR (±0·01) extracted from VASE data of bulk targets and sputtered (Ge28.1Sb6.3Se65.6, Se2) and (Ge12.5Sb25Se62.5, Se6) thin films.](/cms/asset/ae53e73f-3d5e-46db-95aa-b86a0622eac0/yadv_a_1338211_f0003_oc.gif)
Figure 4. (a) SEM image of guiding (Ge12.5Sb25Se62.5, Se6) and cladding (Ge28.1Sb6.3Se65.6, Se2) sputtered layer of mid-IR structure, (b) dispersion curves of refractive indices (±0·01) of the sputtered layers, estimated by the analysis of VASE data via Sellmeier model.
![Figure 4. (a) SEM image of guiding (Ge12.5Sb25Se62.5, Se6) and cladding (Ge28.1Sb6.3Se65.6, Se2) sputtered layer of mid-IR structure, (b) dispersion curves of refractive indices (±0·01) of the sputtered layers, estimated by the analysis of VASE data via Sellmeier model.](/cms/asset/0d8ad5c8-b4f1-4039-a18e-d9d43c9d1744/yadv_a_1338211_f0004_oc.gif)
Figure 5. (a) Scheme and (b) SEM image of cross-section of chalcogenide ridge waveguide, (c) fundamental mode TM00 intensity profile for the optimal geometrical parameters (width w and height h) of chalcogenide waveguide and evolution of the evanescent power factor η as a function of w, h for single-mode propagation in the detection of any substance dissolved at λ = 7·66 μm.
![Figure 5. (a) Scheme and (b) SEM image of cross-section of chalcogenide ridge waveguide, (c) fundamental mode TM00 intensity profile for the optimal geometrical parameters (width w and height h) of chalcogenide waveguide and evolution of the evanescent power factor η as a function of w, h for single-mode propagation in the detection of any substance dissolved at λ = 7·66 μm.](/cms/asset/ed5c7338-c867-4eba-9af8-398683fd074b/yadv_a_1338211_f0005_oc.gif)
Figure 6. (a) Near field of propagated light at λ = 7·7 μm and microscopic image of single-mode ridge waveguides in S-shape configuration. (b) Optical propagation loss at λ = 7·7 μm measured by mode profile imaging method for selenide ridge waveguides with height equal to 1·7 μm and width of 10 μm. Each point represents averaged data for 3 experimental measures.
![Figure 6. (a) Near field of propagated light at λ = 7·7 μm and microscopic image of single-mode ridge waveguides in S-shape configuration. (b) Optical propagation loss at λ = 7·7 μm measured by mode profile imaging method for selenide ridge waveguides with height equal to 1·7 μm and width of 10 μm. Each point represents averaged data for 3 experimental measures.](/cms/asset/1cb2d8a7-92df-4d41-8f24-b55a6af45b37/yadv_a_1338211_f0006_oc.gif)
Figure 7. (a) Mid-IR absorbance spectra of toluene at 100 v/v % and water at T = 278 K. (b) Power transmitted response as a function of the waveguide length taking into consideration the strong absorbance of water in the mid-IR. (c) Scheme of waveguide functionalization: a polymer non-absorbing in the mid-IR is deposited as superstrate for detection of pollutants dissolved in water.
![Figure 7. (a) Mid-IR absorbance spectra of toluene at 100 v/v % and water at T = 278 K. (b) Power transmitted response as a function of the waveguide length taking into consideration the strong absorbance of water in the mid-IR. (c) Scheme of waveguide functionalization: a polymer non-absorbing in the mid-IR is deposited as superstrate for detection of pollutants dissolved in water.](/cms/asset/3aebc26c-5c0d-44f2-b533-950aa8d79682/yadv_a_1338211_f0007_oc.gif)