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)
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)
In this paper, we demonstrate that directly modulated InP short-cavity single-mode VCSEL arrays emitting at 1.55 μm are suitable optical transmitters for metro network applications. We show 400-Gb/s transmission over 400-km standard single mode fiber using a wavelength-division-multiplexed and polarization-division-multiplexed 4-level… (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)