Arrayed waveguide grating spectrometers operating around 800 nm and 1300 nm are demonstrated, with the highest resolution (0.16 nm) and largest free spectral range (77 nm) achieved in silicon-oxynitride technology to date.

Integrated optical probes for detecting backscattered light (i.e. in Raman spectroscopy) show desirable characteristics when compared to conventional fiber probes despite the fact that the latter generally present better collection efficiencies. The major advantages of integrated probes are the reduced size; reduced background noise due to scattering in the probe because of reduced propagation length; potential for monolithic integration with filters, spectrometers and detectors; very small collection volumes, providing high spatial resolution; and polarization maintenance. In our work we demonstrated that in a practically relevant case where scattered light needs to be collected from a thin layer at the samples surface, integrated probes have better collection efficiency than fiber probes do.

We investigate excitation and light collection from a scattering medium by an integrated waveguide probe. A probe with one excitation and eight collector waveguides is fabricated in silicon oxynitride technology. Experiments are performed on light collection from a highly scattering water suspension of latex nanospheres. By use of a Monte Carlo model, the propagation of light through highly scattering media is simulated and good agreement with the experimental data is found.

We have designed a polarization insensitive arrayed-waveguide grating as a wavelength-selective device for Raman spectroscopy of the skin. The integrated spectrometer was characterized. Experimental results are presented and compared with a simulation. We tested our device in a novel confocal arrangement with a similar device that was used for focusing the excitation signal onto the sample. Experimental results on the collection efficiency and volume are presented together with a demonstration of multi-wavelength imaging.

Silicon oxynitride (SiON) is a highly attractive material for integrated optics, due to its excellent properties such as high transparency, adjustable refractive index and good stability. In general, the growth of SiON layers by plasma enhanced chemical vapor deposition (PECVD) is followed by a high temperature annealing step in order to remove hydrogen and to achieve low propagation losses in the 1.5-μm wavelength window. The high annealing temperature (>1100°C) required for sufficient hydrogen removal induces, however, side effects like significant inter-layer diffusion and micro-cracks resulting in deterioration of the device performance. In this paper compositional and optical properties of as-deposited and annealed boron (B) and phosphorous (P) doped SiON layers were investigated. The doped layers have been fabricated by introducing PH3 and B2H6 gaseous precursors into the PECVD process. Hydrogen contents of the samples have been studied by Fourier transform infrared (FTIR) spectroscopy. Compared to undoped film, a 50% reduction of the hydrogen content was measured in as-deposited P-doped SiON layers. Further reduction down to the FTIR detection limit was achieved upon annealing at temperatures as low as 700°C. Besides hydrogen reduction the reflow properties of B and P doped SiON are also highly relevant for the realization of low-loss integrated optical circuits. Reactively ion etched channel waveguides have been reflown applying a temperature of 900°C. Significant reduction of the sidewall roughness has been confirmed by scanning electron microscopy.

Boron or Phosphorous doped PECVD silicon oxynitride layers were fabricated and thermally treated. From the FTIR absorption spectra of the layers, N-H concentrations were obtained as functions of dopant concentration and annealing temperature. Significant reduction of N-H bonds has been observed after annealing at a temperature as low as 700 ̊C. KeywordsSilicon oxynitride, integrated optics, boron and phosphorus doping

Integrated optics potentially can offer significant cost reductions and new applications to Optical Coherence Tomography (OCT). We design, fabricate, and characterize Silicon oxynitride (SiON) elliptic couplers, which can be used to focus light from a chip into the off-chip environment. Fizeau-based OCT measurements are performed with elliptic couplers and a moveable mirror. The optical fields at the output of the elliptic coupler are simulated and measured. Good agreement is observed between the measured OCT signal as a function of depth and calculations based on the optical field at the end of the elliptic coupler.

5% B2H6/Ar and 5% PH3/Ar were introduced to the plasma enhanced chemical vapor deposition process of silicon oxynitride. The bond configurations and refractive indexes of the boron/phosphorous (B/P) doped layers were characterized by Fourier transform infrared spectroscopy and the prism coupling method, respectively. The effect of annealing on the N-H bonds, which mainly contribute to undesired optical losses around 1500 nm wavelength, has been studied. Compared to undoped samples, significant reduction of N-H bonds was observed in the as-deposited B/P doped layers. The reduction of N-H bonds during annealing was found to depend primarily on the applied temperatures rather than on the duration of the annealing process. Complete elimination of N-H bonds has been achieved by temperature treatment of samples at 700åC for 3 hours.