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We review some usual laser range finding techniques for industrial applications. After outlining the basic principles of triangulation and time of flight [pulsed, phase-shift and frequency modulated continuous wave (FMCW)], we discuss their respective fundamental limitations. Selected examples of traditional and new applications are also briefly presented.
1.55-microm vertical cavity surface-emitting low-parasitic lasers show open eyes up to 22-Gb/s modulation speed. Uncooled error-free operation over a wide temperature range up to 85 degrees C under constant bias conditions is demonstrated at 12.5-Gb/s data rate. At these fixed bias conditions the laser characteristics are practically invariant with… (More)
A novel long-wavelength vertical-cavity surface-emitting laser (VCSEL) structure based on a subwavelength high-contrast grating (HCG) as the output mirror has been realized. By design, these devices are highly polarization stable, are single mode at large apertures, and solve the VCSEL-mirror problem at long wavelengths in an elegant way. With… (More)
In this paper, the enhanced high-speed performance and energy-efficiency of 1.3 μm Short-Cavity VCSEL with buried-tunnel-junction is reported. Error-free data-transmission at 30 Gb/s up to 10 km and at 25 Gb/s up to 25 km is performed at room temperature over single mode fiber. Furthermore, low energy-to-data-distance ratios of 24 fJ/(bit·km)… (More)
Optical methods are one of the painless and promising techniques that can be used for blood glucose predictions for diabetes patients. The use of thermally tunable vertical cavity surface-emitting lasers (VCSELs) as the light source to obtain blood absorption spectra, along with the multivariate technique partial least squares for analysis and glucose… (More)
An equivalent-circuit model for a novel 1.55- μm buried tunnel junction vertical-cavity surface-emitting laser chip is proposed based on the structure of the device. The values of the equivalent-circuit elements are determined by fitting the reflection and transmission coefficients at different bias currents. Good agreement between measured and… (More)
In this work, we present three different approaches with the objective of increasing the small-signal modulation bandwidth of InP-based VCSELs beyond 20 GHz. The intrinsic bandwidth limitations are overcome thanks to a highly-strained active region, and an ultra-short cavity design. The parasitic cut-off frequency is enhanced by a double-mesa VCSEL design.
Gradient metasurfaces have recently been demonstrated to provide control of the phase of scattered fields over sub-wavelength scales, enabling a broad range of linear optical components in a flat, ultrathin, integrable platform. Additionally, the development of nonlinear metasurfaces has disrupted conventional nonlinear optical device design by relaxing… (More)