Silicon-on-insulator (SOI) has been used as a platform for nearinfrared photonic devices for more than twenty years. Longer wavelengths, however, may be problematic for SOI due to higher absorption loss in silicon dioxide. In this paper we report propagation loss measurements for the longest wavelength used so far on SOI platform. We show that propagation losses of 0.6-0.7 dB/cm can be achieved at a wavelength of 3.39 µm. We also report propagation loss measurements for silicon on porous silicon (SiPSi) waveguides at the same wavelength.

| In this paper, we present a brief history of silicon photonics from the early research papers in the late 1980s and early 1990s, to the potentially revolutionary technology that exists today. Given that other papers in this special issue give detailed reviews of key aspects of the technology, this paper will concentrate on the key technological milestones that were crucial in demonstrating the capability of silicon photonics as both a successful technical platform, as well as indicating the potential for commercial success. The paper encompasses discussion of the key technology areas of passive devices, modulators, detectors, light sources, and system integration.In so doing, the paper will also serve as an introduction to the other papers within this special issue.

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Abstract:The effect of medium doses of γ-irradiation (1-10 kGy) on total phenolic and tannin contents, lipid peroxidation, protein oxidation intensity and soluble protein content of soybean seeds, (genotype Ana), was investigated. Screening for antioxidant ability was performed using FRAP and DPPH methods. Total phenolic and tannin contents and DPPH scavenger activity were increased, while protein oxidation intensity was decreased by applied doses of γ-irradiation. Gamma irradiation provoked insignificant changes in lipid peroxidation and soluble protein content, while protein oxidation intensity was significantly decreased when dose of 10 kGy was applied. Presented results implicated that increased antioxidant capacity and protein stability of soybean seeds were increased after application of γ-irradiation.

We report on the design, fabrication, and characterization of silicon-on-insulator rib and strip waveguides at wavelengths longer than 3.7 µm. Propagation losses of 1.5±0.2 dB/cm at 3.73 µm and 1.8±0.2 dB/cm at 3.8 µm have been measured for rib waveguides, whilst submicron strip waveguides exhibited propagation losses of 4.6±1.1 dB/cm at the wavelength of 3.74 µm. A 1×2 multimode interference (MMI) splitter and racetrack resonators based on submicron strip waveguides are also examined. Optical losses of 3.6±0.2 dB/MMI and a racetrack resonator Q-value of 8.2 k are obtained at 3.74 µm

In this paper we present a method that allows extraction of the absorption coefficient of a thin film from transmittance spectrum of the film on a silicon substrate. The method essentially removes all “optical effects,” such as interference fringes, reflectance losses, substrate absorption, etc. The method requires that the refractive index of the film is known at one wavelength and that the thickness of the film is approximately known, both of which are generally available from ellipsometric measurements. As a by-product of the procedure, the method also extracts optical constants of the film over the entire spectral range of interest and provides improved values of thickness and refractive index over those provided by ellipsometry.

This is an unusual paper in that it does not address a particular research topic or present a novel experimental method or a new theoretical result. This paper addresses our basic understanding of the nature of the evanescent wave, the wave that is the basis of the entire field of Attenuated Total Reflection (ATR) spectroscopy. I recently had the opportunity to reexamine the foundations of ATR spectroscopy and was surprised to have had to change my own mental picture of the evanescent wave that I have built over the last 25 years. Over the years I have had numerous discussions with a large number of workers in the field as well as with my former mentor, and one of the originators and the principal developer of ATR spectroscopy, the late N.J. Harrick. Everything brought up in all these discussions was perfectly consistent with my old mental picture of the evanescent wave. Thus, I believe that the picture of the evanescent wave that I had is virtually universally held by workers in the field. This paper describes the new picture of the evanescent wave that emerged from said reexamination process.