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Your search keyword '"Micheletti, Paolo"' showing total 3 results
Start Over Author "Micheletti, Paolo" Topic surface emitting lasers
3 results on '"Micheletti, Paolo"'

1. Broadband surface-emitting THz laser frequency combs with inverse-designed integrated reflectors.

Author

Senica, Urban, Gloor, Sebastian, Micheletti, Paolo, Stark, David, Beck, Mattias, Faist, Jérôme, and Scalari, Giacomo

Subjects
SURFACE emitting lasers, QUANTUM cascade lasers, ANTENNA arrays
Abstract

THz quantum cascade lasers (QCLs) based on double metal waveguides feature broadband and high-temperature devices for their use in spectroscopy and sensing. However, their extreme field confinement produces poor output coupling efficiencies and divergent far-fields. Here, we present a planarized THz QCL with an inverse-designed end facet reflector coupled to a surface-emitting patch array antenna. All the components have been optimized for octave-spanning spectral bandwidths between 2 and 4 THz and monolithically integrated on the same photonic chip. We demonstrate this experimentally on broadband THz QCL frequency combs, with measured devices showing a seven-fold improvement in slope efficiency compared to devices with a cleaved facet. They feature a peak power of up to 13.5 mW with surface emission into a narrow beam with a divergence of (17.0° × 18.5°), while broadband fundamental and harmonic comb states spanning up to 800 GHz are observed. [ABSTRACT FROM AUTHOR]

Published
2023
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2. Surface-emitting THz quantum cascade laser frequency comb with tunable external mirror dispersion compensation.

Author

Digiorgio, Valerio, Senica, Urban, Micheletti, Paolo, Beck, Mattias, Faist, Jérôme, and Scalari, Giacomo

Subjects
SUBMILLIMETER waves, SURFACE emitting lasers, OPTICAL dispersion, RIDGE waveguides, LASER cavity resonators
Abstract

We present a surface emitting THz quantum cascade laser frequency comb with an adjustable chromatic dispersion compensation via a mechanically tunable GTI cavity. Surface emission and high optical feedback into the laser cavity are achieved by a planarized ridge waveguide design with low reflectivity facets and two broadband patch array antennas for coupling to an external mirror (back side) and for power extraction (front side). We demonstrate direct and reproducible manipulation of the frequency comb state, specifically the comb stability and beatnote frequency tuning, by controlling the position of an external movable mirror. [ABSTRACT FROM AUTHOR]

Published
2023
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3. Broadband THz quantum cascade laser frequency combs with surface emission and inverse-designed facet reflectors.

Author

Senica, Urban, Gloor, Sebastian, Micheletti, Paolo, Beck, Mattias, Faist, Jérôme, and Scalari, Giacomo

Subjects
BROADBAND communication systems, WAVEGUIDES, BANDWIDTHS, LASER frequency stability, SURFACE emitting lasers
Abstract

We present a planarized waveguide cavity with an integrated broadband output coupler that improves both the output power and far-field properties of THz quantum cascade laser frequency combs. The laser mirror reflectivity can be tuned by the shape of the end facet, which is obtained with an efficient inverse design algorithm, where the structure is iteratively updated to match the desired figure of merit. Surface emission is achieved with a broadband patch-array antenna, and all the components have been optimized for octave-spanning emission spectra (2-4 THz). Experimentally, we demonstrate a broadband surface-emitting THz quantum cascade laser frequency comb with optical bandwidths of up to 800 GHz, surface emission into a narrow beam with divergence below (20° x 20°) and a peak power of 13 mW. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
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